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GCC Code Coverage Report

Directory:	../../../ffmpeg/		Exec	Total	Coverage
File:	src/libavcodec/pgssubdec.c	Lines:	0	281	0.0 %
Date:	2019-11-20 04:07:19	Branches:	0	150	0.0 %


/*
 * PGS subtitle decoder
 * Copyright (c) 2009 Stephen Backway
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * PGS subtitle decoder
 */

#include "avcodec.h"
#include "bytestream.h"
#include "internal.h"
#include "mathops.h"

#include "libavutil/colorspace.h"
#include "libavutil/imgutils.h"
#include "libavutil/opt.h"

#define RGBA(r,g,b,a) (((unsigned)(a) << 24) | ((r) << 16) | ((g) << 8) | (b))
#define MAX_EPOCH_PALETTES 8   // Max 8 allowed per PGS epoch
#define MAX_EPOCH_OBJECTS  64  // Max 64 allowed per PGS epoch
#define MAX_OBJECT_REFS    2   // Max objects per display set

enum SegmentType {
    PALETTE_SEGMENT      = 0x14,
    OBJECT_SEGMENT       = 0x15,
    PRESENTATION_SEGMENT = 0x16,
    WINDOW_SEGMENT       = 0x17,
    DISPLAY_SEGMENT      = 0x80,
};

typedef struct PGSSubObjectRef {
    int     id;
    int     window_id;
    uint8_t composition_flag;
    int     x;
    int     y;
    int     crop_x;
    int     crop_y;
    int     crop_w;
    int     crop_h;
} PGSSubObjectRef;

typedef struct PGSSubPresentation {
    int id_number;
    int palette_id;
    int object_count;
    PGSSubObjectRef objects[MAX_OBJECT_REFS];
    int64_t pts;
} PGSSubPresentation;

typedef struct PGSSubObject {
    int          id;
    int          w;
    int          h;
    uint8_t      *rle;
    unsigned int rle_buffer_size, rle_data_len;
    unsigned int rle_remaining_len;
} PGSSubObject;

typedef struct PGSSubObjects {
    int          count;
    PGSSubObject object[MAX_EPOCH_OBJECTS];
} PGSSubObjects;

typedef struct PGSSubPalette {
    int         id;
    uint32_t    clut[256];
} PGSSubPalette;

typedef struct PGSSubPalettes {
    int           count;
    PGSSubPalette palette[MAX_EPOCH_PALETTES];
} PGSSubPalettes;

typedef struct PGSSubContext {
    AVClass *class;
    PGSSubPresentation presentation;
    PGSSubPalettes     palettes;
    PGSSubObjects      objects;
    int forced_subs_only;
} PGSSubContext;

static void flush_cache(AVCodecContext *avctx)
{
    PGSSubContext *ctx = avctx->priv_data;
    int i;

    for (i = 0; i < ctx->objects.count; i++) {
        av_freep(&ctx->objects.object[i].rle);
        ctx->objects.object[i].rle_buffer_size  = 0;
        ctx->objects.object[i].rle_remaining_len  = 0;
    }
    ctx->objects.count = 0;
    ctx->palettes.count = 0;
}

static PGSSubObject * find_object(int id, PGSSubObjects *objects)
{
    int i;

    for (i = 0; i < objects->count; i++) {
        if (objects->object[i].id == id)
            return &objects->object[i];
    }
    return NULL;
}

static PGSSubPalette * find_palette(int id, PGSSubPalettes *palettes)
{
    int i;

    for (i = 0; i < palettes->count; i++) {
        if (palettes->palette[i].id == id)
            return &palettes->palette[i];
    }
    return NULL;
}

static av_cold int init_decoder(AVCodecContext *avctx)
{
    avctx->pix_fmt     = AV_PIX_FMT_PAL8;

    return 0;
}

static av_cold int close_decoder(AVCodecContext *avctx)
{
    flush_cache(avctx);

    return 0;
}

/**
 * Decode the RLE data.
 *
 * The subtitle is stored as a Run Length Encoded image.
 *
 * @param avctx contains the current codec context
 * @param sub pointer to the processed subtitle data
 * @param buf pointer to the RLE data to process
 * @param buf_size size of the RLE data to process
 */
static int decode_rle(AVCodecContext *avctx, AVSubtitleRect *rect,
                      const uint8_t *buf, unsigned int buf_size)
{
    const uint8_t *rle_bitmap_end;
    int pixel_count, line_count;

    rle_bitmap_end = buf + buf_size;

    rect->data[0] = av_malloc_array(rect->w, rect->h);

    if (!rect->data[0])
        return AVERROR(ENOMEM);

    pixel_count = 0;
    line_count  = 0;

    while (buf < rle_bitmap_end && line_count < rect->h) {
        uint8_t flags, color;
        int run;

        color = bytestream_get_byte(&buf);
        run   = 1;

        if (color == 0x00) {
            flags = bytestream_get_byte(&buf);
            run   = flags & 0x3f;
            if (flags & 0x40)
                run = (run << 8) + bytestream_get_byte(&buf);
            color = flags & 0x80 ? bytestream_get_byte(&buf) : 0;
        }

        if (run > 0 && pixel_count + run <= rect->w * rect->h) {
            memset(rect->data[0] + pixel_count, color, run);
            pixel_count += run;
        } else if (!run) {
            /*
             * New Line. Check if correct pixels decoded, if not display warning
             * and adjust bitmap pointer to correct new line position.
             */
            if (pixel_count % rect->w > 0) {
                av_log(avctx, AV_LOG_ERROR, "Decoded %d pixels, when line should be %d pixels\n",
                       pixel_count % rect->w, rect->w);
                if (avctx->err_recognition & AV_EF_EXPLODE) {
                    return AVERROR_INVALIDDATA;
                }
            }
            line_count++;
        }
    }

    if (pixel_count < rect->w * rect->h) {
        av_log(avctx, AV_LOG_ERROR, "Insufficient RLE data for subtitle\n");
        return AVERROR_INVALIDDATA;
    }

    ff_dlog(avctx, "Pixel Count = %d, Area = %d\n", pixel_count, rect->w * rect->h);

    return 0;
}

/**
 * Parse the picture segment packet.
 *
 * The picture segment contains details on the sequence id,
 * width, height and Run Length Encoded (RLE) bitmap data.
 *
 * @param avctx contains the current codec context
 * @param buf pointer to the packet to process
 * @param buf_size size of packet to process
 */
static int parse_object_segment(AVCodecContext *avctx,
                                  const uint8_t *buf, int buf_size)
{
    PGSSubContext *ctx = avctx->priv_data;
    PGSSubObject *object;

    uint8_t sequence_desc;
    unsigned int rle_bitmap_len, width, height;
    int id;

    if (buf_size <= 4)
        return AVERROR_INVALIDDATA;
    buf_size -= 4;

    id = bytestream_get_be16(&buf);
    object = find_object(id, &ctx->objects);
    if (!object) {
        if (ctx->objects.count >= MAX_EPOCH_OBJECTS) {
            av_log(avctx, AV_LOG_ERROR, "Too many objects in epoch\n");
            return AVERROR_INVALIDDATA;
        }
        object = &ctx->objects.object[ctx->objects.count++];
        object->id = id;
    }

    /* skip object version number */
    buf += 1;

    /* Read the Sequence Description to determine if start of RLE data or appended to previous RLE */
    sequence_desc = bytestream_get_byte(&buf);

    if (!(sequence_desc & 0x80)) {
        /* Additional RLE data */
        if (buf_size > object->rle_remaining_len)
            return AVERROR_INVALIDDATA;

        memcpy(object->rle + object->rle_data_len, buf, buf_size);
        object->rle_data_len += buf_size;
        object->rle_remaining_len -= buf_size;

        return 0;
    }

    if (buf_size <= 7)
        return AVERROR_INVALIDDATA;
    buf_size -= 7;

    /* Decode rle bitmap length, stored size includes width/height data */
    rle_bitmap_len = bytestream_get_be24(&buf) - 2*2;

    if (buf_size > rle_bitmap_len) {
        av_log(avctx, AV_LOG_ERROR,
               "Buffer dimension %d larger than the expected RLE data %d\n",
               buf_size, rle_bitmap_len);
        return AVERROR_INVALIDDATA;
    }

    /* Get bitmap dimensions from data */
    width  = bytestream_get_be16(&buf);
    height = bytestream_get_be16(&buf);

    /* Make sure the bitmap is not too large */
    if (avctx->width < width || avctx->height < height || !width || !height) {
        av_log(avctx, AV_LOG_ERROR, "Bitmap dimensions (%dx%d) invalid.\n", width, height);
        return AVERROR_INVALIDDATA;
    }

    object->w = width;
    object->h = height;

    av_fast_padded_malloc(&object->rle, &object->rle_buffer_size, rle_bitmap_len);

    if (!object->rle) {
        object->rle_data_len = 0;
        object->rle_remaining_len = 0;
        return AVERROR(ENOMEM);
    }

    memcpy(object->rle, buf, buf_size);
    object->rle_data_len = buf_size;
    object->rle_remaining_len = rle_bitmap_len - buf_size;

    return 0;
}

/**
 * Parse the palette segment packet.
 *
 * The palette segment contains details of the palette,
 * a maximum of 256 colors can be defined.
 *
 * @param avctx contains the current codec context
 * @param buf pointer to the packet to process
 * @param buf_size size of packet to process
 */
static int parse_palette_segment(AVCodecContext *avctx,
                                  const uint8_t *buf, int buf_size)
{
    PGSSubContext *ctx = avctx->priv_data;
    PGSSubPalette *palette;

    const uint8_t *buf_end = buf + buf_size;
    const uint8_t *cm      = ff_crop_tab + MAX_NEG_CROP;
    int color_id;
    int y, cb, cr, alpha;
    int r, g, b, r_add, g_add, b_add;
    int id;

    id  = bytestream_get_byte(&buf);
    palette = find_palette(id, &ctx->palettes);
    if (!palette) {
        if (ctx->palettes.count >= MAX_EPOCH_PALETTES) {
            av_log(avctx, AV_LOG_ERROR, "Too many palettes in epoch\n");
            return AVERROR_INVALIDDATA;
        }
        palette = &ctx->palettes.palette[ctx->palettes.count++];
        palette->id  = id;
    }

    /* Skip palette version */
    buf += 1;

    while (buf < buf_end) {
        color_id  = bytestream_get_byte(&buf);
        y         = bytestream_get_byte(&buf);
        cr        = bytestream_get_byte(&buf);
        cb        = bytestream_get_byte(&buf);
        alpha     = bytestream_get_byte(&buf);

        /* Default to BT.709 colorspace. In case of <= 576 height use BT.601 */
        if (avctx->height <= 0 || avctx->height > 576) {
            YUV_TO_RGB1_CCIR_BT709(cb, cr);
        } else {
            YUV_TO_RGB1_CCIR(cb, cr);
        }

        YUV_TO_RGB2_CCIR(r, g, b, y);

        ff_dlog(avctx, "Color %d := (%d,%d,%d,%d)\n", color_id, r, g, b, alpha);

        /* Store color in palette */
        palette->clut[color_id] = RGBA(r,g,b,alpha);
    }
    return 0;
}

/**
 * Parse the presentation segment packet.
 *
 * The presentation segment contains details on the video
 * width, video height, x & y subtitle position.
 *
 * @param avctx contains the current codec context
 * @param buf pointer to the packet to process
 * @param buf_size size of packet to process
 * @todo TODO: Implement cropping
 */
static int parse_presentation_segment(AVCodecContext *avctx,
                                      const uint8_t *buf, int buf_size,
                                      int64_t pts)
{
    PGSSubContext *ctx = avctx->priv_data;
    int i, state, ret;
    const uint8_t *buf_end = buf + buf_size;

    // Video descriptor
    int w = bytestream_get_be16(&buf);
    int h = bytestream_get_be16(&buf);

    ctx->presentation.pts = pts;

    ff_dlog(avctx, "Video Dimensions %dx%d\n",
            w, h);
    ret = ff_set_dimensions(avctx, w, h);
    if (ret < 0)
        return ret;

    /* Skip 1 bytes of unknown, frame rate */
    buf++;

    // Composition descriptor
    ctx->presentation.id_number = bytestream_get_be16(&buf);
    /*
     * state is a 2 bit field that defines pgs epoch boundaries
     * 00 - Normal, previously defined objects and palettes are still valid
     * 01 - Acquisition point, previous objects and palettes can be released
     * 10 - Epoch start, previous objects and palettes can be released
     * 11 - Epoch continue, previous objects and palettes can be released
     *
     * reserved 6 bits discarded
     */
    state = bytestream_get_byte(&buf) >> 6;
    if (state != 0) {
        flush_cache(avctx);
    }

    /*
     * skip palette_update_flag (0x80),
     */
    buf += 1;
    ctx->presentation.palette_id = bytestream_get_byte(&buf);
    ctx->presentation.object_count = bytestream_get_byte(&buf);
    if (ctx->presentation.object_count > MAX_OBJECT_REFS) {
        av_log(avctx, AV_LOG_ERROR,
               "Invalid number of presentation objects %d\n",
               ctx->presentation.object_count);
        ctx->presentation.object_count = 2;
        if (avctx->err_recognition & AV_EF_EXPLODE) {
            return AVERROR_INVALIDDATA;
        }
    }


    for (i = 0; i < ctx->presentation.object_count; i++)
    {

        if (buf_end - buf < 8) {
            av_log(avctx, AV_LOG_ERROR, "Insufficent space for object\n");
            ctx->presentation.object_count = i;
            return AVERROR_INVALIDDATA;
        }

        ctx->presentation.objects[i].id = bytestream_get_be16(&buf);
        ctx->presentation.objects[i].window_id = bytestream_get_byte(&buf);
        ctx->presentation.objects[i].composition_flag = bytestream_get_byte(&buf);

        ctx->presentation.objects[i].x = bytestream_get_be16(&buf);
        ctx->presentation.objects[i].y = bytestream_get_be16(&buf);

        // If cropping
        if (ctx->presentation.objects[i].composition_flag & 0x80) {
            ctx->presentation.objects[i].crop_x = bytestream_get_be16(&buf);
            ctx->presentation.objects[i].crop_y = bytestream_get_be16(&buf);
            ctx->presentation.objects[i].crop_w = bytestream_get_be16(&buf);
            ctx->presentation.objects[i].crop_h = bytestream_get_be16(&buf);
        }

        ff_dlog(avctx, "Subtitle Placement x=%d, y=%d\n",
                ctx->presentation.objects[i].x, ctx->presentation.objects[i].y);

        if (ctx->presentation.objects[i].x > avctx->width ||
            ctx->presentation.objects[i].y > avctx->height) {
            av_log(avctx, AV_LOG_ERROR, "Subtitle out of video bounds. x = %d, y = %d, video width = %d, video height = %d.\n",
                   ctx->presentation.objects[i].x,
                   ctx->presentation.objects[i].y,
                    avctx->width, avctx->height);
            ctx->presentation.objects[i].x = 0;
            ctx->presentation.objects[i].y = 0;
            if (avctx->err_recognition & AV_EF_EXPLODE) {
                return AVERROR_INVALIDDATA;
            }
        }
    }

    return 0;
}

/**
 * Parse the display segment packet.
 *
 * The display segment controls the updating of the display.
 *
 * @param avctx contains the current codec context
 * @param data pointer to the data pertaining the subtitle to display
 * @param buf pointer to the packet to process
 * @param buf_size size of packet to process
 */
static int display_end_segment(AVCodecContext *avctx, void *data,
                               const uint8_t *buf, int buf_size)
{
    AVSubtitle    *sub = data;
    PGSSubContext *ctx = avctx->priv_data;
    int64_t pts;
    PGSSubPalette *palette;
    int i, ret;

    pts = ctx->presentation.pts != AV_NOPTS_VALUE ? ctx->presentation.pts : sub->pts;
    memset(sub, 0, sizeof(*sub));
    sub->pts = pts;
    ctx->presentation.pts = AV_NOPTS_VALUE;
    sub->start_display_time = 0;
    // There is no explicit end time for PGS subtitles.  The end time
    // is defined by the start of the next sub which may contain no
    // objects (i.e. clears the previous sub)
    sub->end_display_time   = UINT32_MAX;
    sub->format             = 0;

    // Blank if last object_count was 0.
    if (!ctx->presentation.object_count)
        return 1;
    sub->rects = av_mallocz_array(ctx->presentation.object_count, sizeof(*sub->rects));
    if (!sub->rects) {
        return AVERROR(ENOMEM);
    }
    palette = find_palette(ctx->presentation.palette_id, &ctx->palettes);
    if (!palette) {
        // Missing palette.  Should only happen with damaged streams.
        av_log(avctx, AV_LOG_ERROR, "Invalid palette id %d\n",
               ctx->presentation.palette_id);
        avsubtitle_free(sub);
        return AVERROR_INVALIDDATA;
    }
    for (i = 0; i < ctx->presentation.object_count; i++) {
        PGSSubObject *object;

        sub->rects[i]  = av_mallocz(sizeof(*sub->rects[0]));
        if (!sub->rects[i]) {
            avsubtitle_free(sub);
            return AVERROR(ENOMEM);
        }
        sub->num_rects++;
        sub->rects[i]->type = SUBTITLE_BITMAP;

        /* Process bitmap */
        object = find_object(ctx->presentation.objects[i].id, &ctx->objects);
        if (!object) {
            // Missing object.  Should only happen with damaged streams.
            av_log(avctx, AV_LOG_ERROR, "Invalid object id %d\n",
                   ctx->presentation.objects[i].id);
            if (avctx->err_recognition & AV_EF_EXPLODE) {
                avsubtitle_free(sub);
                return AVERROR_INVALIDDATA;
            }
            // Leaves rect empty with 0 width and height.
            continue;
        }
        if (ctx->presentation.objects[i].composition_flag & 0x40)
            sub->rects[i]->flags |= AV_SUBTITLE_FLAG_FORCED;

        sub->rects[i]->x    = ctx->presentation.objects[i].x;
        sub->rects[i]->y    = ctx->presentation.objects[i].y;

        if (object->rle) {
            sub->rects[i]->w    = object->w;
            sub->rects[i]->h    = object->h;

            sub->rects[i]->linesize[0] = object->w;

            if (object->rle_remaining_len) {
                av_log(avctx, AV_LOG_ERROR, "RLE data length %u is %u bytes shorter than expected\n",
                       object->rle_data_len, object->rle_remaining_len);
                if (avctx->err_recognition & AV_EF_EXPLODE) {
                    avsubtitle_free(sub);
                    return AVERROR_INVALIDDATA;
                }
            }
            ret = decode_rle(avctx, sub->rects[i], object->rle, object->rle_data_len);
            if (ret < 0) {
                if ((avctx->err_recognition & AV_EF_EXPLODE) ||
                    ret == AVERROR(ENOMEM)) {
                    avsubtitle_free(sub);
                    return ret;
                }
                sub->rects[i]->w = 0;
                sub->rects[i]->h = 0;
                continue;
            }
        }
        /* Allocate memory for colors */
        sub->rects[i]->nb_colors    = 256;
        sub->rects[i]->data[1] = av_mallocz(AVPALETTE_SIZE);
        if (!sub->rects[i]->data[1]) {
            avsubtitle_free(sub);
            return AVERROR(ENOMEM);
        }

        if (!ctx->forced_subs_only || ctx->presentation.objects[i].composition_flag & 0x40)
        memcpy(sub->rects[i]->data[1], palette->clut, sub->rects[i]->nb_colors * sizeof(uint32_t));

#if FF_API_AVPICTURE
FF_DISABLE_DEPRECATION_WARNINGS
{
        AVSubtitleRect *rect;
        int j;
        rect = sub->rects[i];
        for (j = 0; j < 4; j++) {
            rect->pict.data[j] = rect->data[j];
            rect->pict.linesize[j] = rect->linesize[j];
        }
}
FF_ENABLE_DEPRECATION_WARNINGS
#endif
    }
    return 1;
}

static int decode(AVCodecContext *avctx, void *data, int *data_size,
                  AVPacket *avpkt)
{
    const uint8_t *buf = avpkt->data;
    int buf_size       = avpkt->size;

    const uint8_t *buf_end;
    uint8_t       segment_type;
    int           segment_length;
    int i, ret;

    ff_dlog(avctx, "PGS sub packet:\n");

    for (i = 0; i < buf_size; i++) {
        ff_dlog(avctx, "%02x ", buf[i]);
        if (i % 16 == 15)
            ff_dlog(avctx, "\n");
    }

    if (i & 15)
        ff_dlog(avctx, "\n");

    *data_size = 0;

    /* Ensure that we have received at a least a segment code and segment length */
    if (buf_size < 3)
        return -1;

    buf_end = buf + buf_size;

    /* Step through buffer to identify segments */
    while (buf < buf_end) {
        segment_type   = bytestream_get_byte(&buf);
        segment_length = bytestream_get_be16(&buf);

        ff_dlog(avctx, "Segment Length %d, Segment Type %x\n", segment_length, segment_type);

        if (segment_type != DISPLAY_SEGMENT && segment_length > buf_end - buf)
            break;

        ret = 0;
        switch (segment_type) {
        case PALETTE_SEGMENT:
            ret = parse_palette_segment(avctx, buf, segment_length);
            break;
        case OBJECT_SEGMENT:
            ret = parse_object_segment(avctx, buf, segment_length);
            break;
        case PRESENTATION_SEGMENT:
            ret = parse_presentation_segment(avctx, buf, segment_length, ((AVSubtitle*)(data))->pts);
            break;
        case WINDOW_SEGMENT:
            /*
             * Window Segment Structure (No new information provided):
             *     2 bytes: Unknown,
             *     2 bytes: X position of subtitle,
             *     2 bytes: Y position of subtitle,
             *     2 bytes: Width of subtitle,
             *     2 bytes: Height of subtitle.
             */
            break;
        case DISPLAY_SEGMENT:
            if (*data_size) {
                av_log(avctx, AV_LOG_ERROR, "Duplicate display segment\n");
                ret = AVERROR_INVALIDDATA;
                break;
            }
            ret = display_end_segment(avctx, data, buf, segment_length);
            if (ret >= 0)
                *data_size = ret;
            break;
        default:
            av_log(avctx, AV_LOG_ERROR, "Unknown subtitle segment type 0x%x, length %d\n",
                   segment_type, segment_length);
            ret = AVERROR_INVALIDDATA;
            break;
        }
        if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
            return ret;

        buf += segment_length;
    }

    return buf_size;
}

#define OFFSET(x) offsetof(PGSSubContext, x)
#define SD AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_DECODING_PARAM
static const AVOption options[] = {
    {"forced_subs_only", "Only show forced subtitles", OFFSET(forced_subs_only), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, SD},
    { NULL },
};

static const AVClass pgsdec_class = {
    .class_name = "PGS subtitle decoder",
    .item_name  = av_default_item_name,
    .option     = options,
    .version    = LIBAVUTIL_VERSION_INT,
};

AVCodec ff_pgssub_decoder = {
    .name           = "pgssub",
    .long_name      = NULL_IF_CONFIG_SMALL("HDMV Presentation Graphic Stream subtitles"),
    .type           = AVMEDIA_TYPE_SUBTITLE,
    .id             = AV_CODEC_ID_HDMV_PGS_SUBTITLE,
    .priv_data_size = sizeof(PGSSubContext),
    .init           = init_decoder,
    .close          = close_decoder,
    .decode         = decode,
    .priv_class     = &pgsdec_class,
};


Generated by: GCOVR (Version 4.1)

Line	Branch	Exec	Source
1			/*
2			* PGS subtitle decoder
3			* Copyright (c) 2009 Stephen Backway
4			*
5			* This file is part of FFmpeg.
6			*
7			* FFmpeg is free software; you can redistribute it and/or
8			* modify it under the terms of the GNU Lesser General Public
9			* License as published by the Free Software Foundation; either
10			* version 2.1 of the License, or (at your option) any later version.
11			*
12			* FFmpeg is distributed in the hope that it will be useful,
13			* but WITHOUT ANY WARRANTY; without even the implied warranty of
14			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15			* Lesser General Public License for more details.
16			*
17			* You should have received a copy of the GNU Lesser General Public
18			* License along with FFmpeg; if not, write to the Free Software
19			* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20			*/
21
22			/**
23			* @file
24			* PGS subtitle decoder
25			*/
26
27			#include "avcodec.h"
28			#include "bytestream.h"
29			#include "internal.h"
30			#include "mathops.h"
31
32			#include "libavutil/colorspace.h"
33			#include "libavutil/imgutils.h"
34			#include "libavutil/opt.h"
35
36			#define RGBA(r,g,b,a) (((unsigned)(a) << 24) \| ((r) << 16) \| ((g) << 8) \| (b))
37			#define MAX_EPOCH_PALETTES 8 // Max 8 allowed per PGS epoch
38			#define MAX_EPOCH_OBJECTS 64 // Max 64 allowed per PGS epoch
39			#define MAX_OBJECT_REFS 2 // Max objects per display set
40
41			enum SegmentType {
42			PALETTE_SEGMENT = 0x14,
43			OBJECT_SEGMENT = 0x15,
44			PRESENTATION_SEGMENT = 0x16,
45			WINDOW_SEGMENT = 0x17,
46			DISPLAY_SEGMENT = 0x80,
47			};
48
49			typedef struct PGSSubObjectRef {
50			int id;
51			int window_id;
52			uint8_t composition_flag;
53			int x;
54			int y;
55			int crop_x;
56			int crop_y;
57			int crop_w;
58			int crop_h;
59			} PGSSubObjectRef;
60
61			typedef struct PGSSubPresentation {
62			int id_number;
63			int palette_id;
64			int object_count;
65			PGSSubObjectRef objects[MAX_OBJECT_REFS];
66			int64_t pts;
67			} PGSSubPresentation;
68
69			typedef struct PGSSubObject {
70			int id;
71			int w;
72			int h;
73			uint8_t *rle;
74			unsigned int rle_buffer_size, rle_data_len;
75			unsigned int rle_remaining_len;
76			} PGSSubObject;
77
78			typedef struct PGSSubObjects {
79			int count;
80			PGSSubObject object[MAX_EPOCH_OBJECTS];
81			} PGSSubObjects;
82
83			typedef struct PGSSubPalette {
84			int id;
85			uint32_t clut[256];
86			} PGSSubPalette;
87
88			typedef struct PGSSubPalettes {
89			int count;
90			PGSSubPalette palette[MAX_EPOCH_PALETTES];
91			} PGSSubPalettes;
92
93			typedef struct PGSSubContext {
94			AVClass *class;
95			PGSSubPresentation presentation;
96			PGSSubPalettes palettes;
97			PGSSubObjects objects;
98			int forced_subs_only;
99			} PGSSubContext;
100
101			static void flush_cache(AVCodecContext *avctx)
102			{
103			PGSSubContext *ctx = avctx->priv_data;
104			int i;
105
106			for (i = 0; i < ctx->objects.count; i++) {
107			av_freep(&ctx->objects.object[i].rle);
108			ctx->objects.object[i].rle_buffer_size = 0;
109			ctx->objects.object[i].rle_remaining_len = 0;
110			}
111			ctx->objects.count = 0;
112			ctx->palettes.count = 0;
113			}
114
115			static PGSSubObject * find_object(int id, PGSSubObjects *objects)
116			{
117			int i;
118
119			for (i = 0; i < objects->count; i++) {
120			if (objects->object[i].id == id)
121			return &objects->object[i];
122			}
123			return NULL;
124			}
125
126			static PGSSubPalette * find_palette(int id, PGSSubPalettes *palettes)
127			{
128			int i;
129
130			for (i = 0; i < palettes->count; i++) {
131			if (palettes->palette[i].id == id)
132			return &palettes->palette[i];
133			}
134			return NULL;
135			}
136
137			static av_cold int init_decoder(AVCodecContext *avctx)
138			{
139			avctx->pix_fmt = AV_PIX_FMT_PAL8;
140
141			return 0;
142			}
143
144			static av_cold int close_decoder(AVCodecContext *avctx)
145			{
146			flush_cache(avctx);
147
148			return 0;
149			}
150
151			/**
152			* Decode the RLE data.
153			*
154			* The subtitle is stored as a Run Length Encoded image.
155			*
156			* @param avctx contains the current codec context
157			* @param sub pointer to the processed subtitle data
158			* @param buf pointer to the RLE data to process
159			* @param buf_size size of the RLE data to process
160			*/
161			static int decode_rle(AVCodecContext avctx, AVSubtitleRect rect,
162			const uint8_t *buf, unsigned int buf_size)
163			{
164			const uint8_t *rle_bitmap_end;
165			int pixel_count, line_count;
166
167			rle_bitmap_end = buf + buf_size;
168
169			rect->data[0] = av_malloc_array(rect->w, rect->h);
170
171			if (!rect->data[0])
172			return AVERROR(ENOMEM);
173
174			pixel_count = 0;
175			line_count = 0;
176
177			while (buf < rle_bitmap_end && line_count < rect->h) {
178			uint8_t flags, color;
179			int run;
180
181			color = bytestream_get_byte(&buf);
182			run = 1;
183
184			if (color == 0x00) {
185			flags = bytestream_get_byte(&buf);
186			run = flags & 0x3f;
187			if (flags & 0x40)
188			run = (run << 8) + bytestream_get_byte(&buf);
189			color = flags & 0x80 ? bytestream_get_byte(&buf) : 0;
190			}
191
192			if (run > 0 && pixel_count + run <= rect->w * rect->h) {
193			memset(rect->data[0] + pixel_count, color, run);
194			pixel_count += run;
195			} else if (!run) {
196			/*
197			* New Line. Check if correct pixels decoded, if not display warning
198			* and adjust bitmap pointer to correct new line position.
199			*/
200			if (pixel_count % rect->w > 0) {
201			av_log(avctx, AV_LOG_ERROR, "Decoded %d pixels, when line should be %d pixels\n",
202			pixel_count % rect->w, rect->w);
203			if (avctx->err_recognition & AV_EF_EXPLODE) {
204			return AVERROR_INVALIDDATA;
205			}
206			}
207			line_count++;
208			}
209			}
210
211			if (pixel_count < rect->w * rect->h) {
212			av_log(avctx, AV_LOG_ERROR, "Insufficient RLE data for subtitle\n");
213			return AVERROR_INVALIDDATA;
214			}
215
216			ff_dlog(avctx, "Pixel Count = %d, Area = %d\n", pixel_count, rect->w * rect->h);
217
218			return 0;
219			}
220
221			/**
222			* Parse the picture segment packet.
223			*
224			* The picture segment contains details on the sequence id,
225			* width, height and Run Length Encoded (RLE) bitmap data.
226			*
227			* @param avctx contains the current codec context
228			* @param buf pointer to the packet to process
229			* @param buf_size size of packet to process
230			*/
231			static int parse_object_segment(AVCodecContext *avctx,
232			const uint8_t *buf, int buf_size)
233			{
234			PGSSubContext *ctx = avctx->priv_data;
235			PGSSubObject *object;
236
237			uint8_t sequence_desc;
238			unsigned int rle_bitmap_len, width, height;
239			int id;
240
241			if (buf_size <= 4)
242			return AVERROR_INVALIDDATA;
243			buf_size -= 4;
244
245			id = bytestream_get_be16(&buf);
246			object = find_object(id, &ctx->objects);
247			if (!object) {
248			if (ctx->objects.count >= MAX_EPOCH_OBJECTS) {
249			av_log(avctx, AV_LOG_ERROR, "Too many objects in epoch\n");
250			return AVERROR_INVALIDDATA;
251			}
252			object = &ctx->objects.object[ctx->objects.count++];
253			object->id = id;
254			}
255
256			/* skip object version number */
257			buf += 1;
258
259			/* Read the Sequence Description to determine if start of RLE data or appended to previous RLE */
260			sequence_desc = bytestream_get_byte(&buf);
261
262			if (!(sequence_desc & 0x80)) {
263			/* Additional RLE data */
264			if (buf_size > object->rle_remaining_len)
265			return AVERROR_INVALIDDATA;
266
267			memcpy(object->rle + object->rle_data_len, buf, buf_size);
268			object->rle_data_len += buf_size;
269			object->rle_remaining_len -= buf_size;
270
271			return 0;
272			}
273
274			if (buf_size <= 7)
275			return AVERROR_INVALIDDATA;
276			buf_size -= 7;
277
278			/* Decode rle bitmap length, stored size includes width/height data */
279			rle_bitmap_len = bytestream_get_be24(&buf) - 2*2;
280
281			if (buf_size > rle_bitmap_len) {
282			av_log(avctx, AV_LOG_ERROR,
283			"Buffer dimension %d larger than the expected RLE data %d\n",
284			buf_size, rle_bitmap_len);
285			return AVERROR_INVALIDDATA;
286			}
287
288			/* Get bitmap dimensions from data */
289			width = bytestream_get_be16(&buf);
290			height = bytestream_get_be16(&buf);
291
292			/* Make sure the bitmap is not too large */
293			if (avctx->width < width \|\| avctx->height < height \|\| !width \|\| !height) {
294			av_log(avctx, AV_LOG_ERROR, "Bitmap dimensions (%dx%d) invalid.\n", width, height);
295			return AVERROR_INVALIDDATA;
296			}
297
298			object->w = width;
299			object->h = height;
300
301			av_fast_padded_malloc(&object->rle, &object->rle_buffer_size, rle_bitmap_len);
302
303			if (!object->rle) {
304			object->rle_data_len = 0;
305			object->rle_remaining_len = 0;
306			return AVERROR(ENOMEM);
307			}
308
309			memcpy(object->rle, buf, buf_size);
310			object->rle_data_len = buf_size;
311			object->rle_remaining_len = rle_bitmap_len - buf_size;
312
313			return 0;
314			}
315
316			/**
317			* Parse the palette segment packet.
318			*
319			* The palette segment contains details of the palette,
320			* a maximum of 256 colors can be defined.
321			*
322			* @param avctx contains the current codec context
323			* @param buf pointer to the packet to process
324			* @param buf_size size of packet to process
325			*/
326			static int parse_palette_segment(AVCodecContext *avctx,
327			const uint8_t *buf, int buf_size)
328			{
329			PGSSubContext *ctx = avctx->priv_data;
330			PGSSubPalette *palette;
331
332			const uint8_t *buf_end = buf + buf_size;
333			const uint8_t *cm = ff_crop_tab + MAX_NEG_CROP;
334			int color_id;
335			int y, cb, cr, alpha;
336			int r, g, b, r_add, g_add, b_add;
337			int id;
338
339			id = bytestream_get_byte(&buf);
340			palette = find_palette(id, &ctx->palettes);
341			if (!palette) {
342			if (ctx->palettes.count >= MAX_EPOCH_PALETTES) {
343			av_log(avctx, AV_LOG_ERROR, "Too many palettes in epoch\n");
344			return AVERROR_INVALIDDATA;
345			}
346			palette = &ctx->palettes.palette[ctx->palettes.count++];
347			palette->id = id;
348			}
349
350			/* Skip palette version */
351			buf += 1;
352
353			while (buf < buf_end) {
354			color_id = bytestream_get_byte(&buf);
355			y = bytestream_get_byte(&buf);
356			cr = bytestream_get_byte(&buf);
357			cb = bytestream_get_byte(&buf);
358			alpha = bytestream_get_byte(&buf);
359
360			/* Default to BT.709 colorspace. In case of <= 576 height use BT.601 */
361			if (avctx->height <= 0 \|\| avctx->height > 576) {
362			YUV_TO_RGB1_CCIR_BT709(cb, cr);
363			} else {
364			YUV_TO_RGB1_CCIR(cb, cr);
365			}
366
367			YUV_TO_RGB2_CCIR(r, g, b, y);
368
369			ff_dlog(avctx, "Color %d := (%d,%d,%d,%d)\n", color_id, r, g, b, alpha);
370
371			/* Store color in palette */
372			palette->clut[color_id] = RGBA(r,g,b,alpha);
373			}
374			return 0;
375			}
376
377			/**
378			* Parse the presentation segment packet.
379			*
380			* The presentation segment contains details on the video
381			* width, video height, x & y subtitle position.
382			*
383			* @param avctx contains the current codec context
384			* @param buf pointer to the packet to process
385			* @param buf_size size of packet to process
386			* @todo TODO: Implement cropping
387			*/
388			static int parse_presentation_segment(AVCodecContext *avctx,
389			const uint8_t *buf, int buf_size,
390			int64_t pts)
391			{
392			PGSSubContext *ctx = avctx->priv_data;
393			int i, state, ret;
394			const uint8_t *buf_end = buf + buf_size;
395
396			// Video descriptor
397			int w = bytestream_get_be16(&buf);
398			int h = bytestream_get_be16(&buf);
399
400			ctx->presentation.pts = pts;
401
402			ff_dlog(avctx, "Video Dimensions %dx%d\n",
403			w, h);
404			ret = ff_set_dimensions(avctx, w, h);
405			if (ret < 0)
406			return ret;
407
408			/* Skip 1 bytes of unknown, frame rate */
409			buf++;
410
411			// Composition descriptor
412			ctx->presentation.id_number = bytestream_get_be16(&buf);
413			/*
414			* state is a 2 bit field that defines pgs epoch boundaries
415			* 00 - Normal, previously defined objects and palettes are still valid
416			* 01 - Acquisition point, previous objects and palettes can be released
417			* 10 - Epoch start, previous objects and palettes can be released
418			* 11 - Epoch continue, previous objects and palettes can be released
419			*
420			* reserved 6 bits discarded
421			*/
422			state = bytestream_get_byte(&buf) >> 6;
423			if (state != 0) {
424			flush_cache(avctx);
425			}
426
427			/*
428			* skip palette_update_flag (0x80),
429			*/
430			buf += 1;
431			ctx->presentation.palette_id = bytestream_get_byte(&buf);
432			ctx->presentation.object_count = bytestream_get_byte(&buf);
433			if (ctx->presentation.object_count > MAX_OBJECT_REFS) {
434			av_log(avctx, AV_LOG_ERROR,
435			"Invalid number of presentation objects %d\n",
436			ctx->presentation.object_count);
437			ctx->presentation.object_count = 2;
438			if (avctx->err_recognition & AV_EF_EXPLODE) {
439			return AVERROR_INVALIDDATA;
440			}
441			}
442
443
444			for (i = 0; i < ctx->presentation.object_count; i++)
445			{
446
447			if (buf_end - buf < 8) {
448			av_log(avctx, AV_LOG_ERROR, "Insufficent space for object\n");
449			ctx->presentation.object_count = i;
450			return AVERROR_INVALIDDATA;
451			}
452
453			ctx->presentation.objects[i].id = bytestream_get_be16(&buf);
454			ctx->presentation.objects[i].window_id = bytestream_get_byte(&buf);
455			ctx->presentation.objects[i].composition_flag = bytestream_get_byte(&buf);
456
457			ctx->presentation.objects[i].x = bytestream_get_be16(&buf);
458			ctx->presentation.objects[i].y = bytestream_get_be16(&buf);
459
460			// If cropping
461			if (ctx->presentation.objects[i].composition_flag & 0x80) {
462			ctx->presentation.objects[i].crop_x = bytestream_get_be16(&buf);
463			ctx->presentation.objects[i].crop_y = bytestream_get_be16(&buf);
464			ctx->presentation.objects[i].crop_w = bytestream_get_be16(&buf);
465			ctx->presentation.objects[i].crop_h = bytestream_get_be16(&buf);
466			}
467
468			ff_dlog(avctx, "Subtitle Placement x=%d, y=%d\n",
469			ctx->presentation.objects[i].x, ctx->presentation.objects[i].y);
470
471			if (ctx->presentation.objects[i].x > avctx->width \|\|
472			ctx->presentation.objects[i].y > avctx->height) {
473			av_log(avctx, AV_LOG_ERROR, "Subtitle out of video bounds. x = %d, y = %d, video width = %d, video height = %d.\n",
474			ctx->presentation.objects[i].x,
475			ctx->presentation.objects[i].y,
476			avctx->width, avctx->height);
477			ctx->presentation.objects[i].x = 0;
478			ctx->presentation.objects[i].y = 0;
479			if (avctx->err_recognition & AV_EF_EXPLODE) {
480			return AVERROR_INVALIDDATA;
481			}
482			}
483			}
484
485			return 0;
486			}
487
488			/**
489			* Parse the display segment packet.
490			*
491			* The display segment controls the updating of the display.
492			*
493			* @param avctx contains the current codec context
494			* @param data pointer to the data pertaining the subtitle to display
495			* @param buf pointer to the packet to process
496			* @param buf_size size of packet to process
497			*/
498			static int display_end_segment(AVCodecContext avctx, void data,
499			const uint8_t *buf, int buf_size)
500			{
501			AVSubtitle *sub = data;
502			PGSSubContext *ctx = avctx->priv_data;
503			int64_t pts;
504			PGSSubPalette *palette;
505			int i, ret;
506
507			pts = ctx->presentation.pts != AV_NOPTS_VALUE ? ctx->presentation.pts : sub->pts;
508			memset(sub, 0, sizeof(*sub));
509			sub->pts = pts;
510			ctx->presentation.pts = AV_NOPTS_VALUE;
511			sub->start_display_time = 0;
512			// There is no explicit end time for PGS subtitles. The end time
513			// is defined by the start of the next sub which may contain no
514			// objects (i.e. clears the previous sub)
515			sub->end_display_time = UINT32_MAX;
516			sub->format = 0;
517
518			// Blank if last object_count was 0.
519			if (!ctx->presentation.object_count)
520			return 1;
521			sub->rects = av_mallocz_array(ctx->presentation.object_count, sizeof(*sub->rects));
522			if (!sub->rects) {
523			return AVERROR(ENOMEM);
524			}
525			palette = find_palette(ctx->presentation.palette_id, &ctx->palettes);
526			if (!palette) {
527			// Missing palette. Should only happen with damaged streams.
528			av_log(avctx, AV_LOG_ERROR, "Invalid palette id %d\n",
529			ctx->presentation.palette_id);
530			avsubtitle_free(sub);
531			return AVERROR_INVALIDDATA;
532			}
533			for (i = 0; i < ctx->presentation.object_count; i++) {
534			PGSSubObject *object;
535
536			sub->rects[i] = av_mallocz(sizeof(*sub->rects[0]));
537			if (!sub->rects[i]) {
538			avsubtitle_free(sub);
539			return AVERROR(ENOMEM);
540			}
541			sub->num_rects++;
542			sub->rects[i]->type = SUBTITLE_BITMAP;
543
544			/* Process bitmap */
545			object = find_object(ctx->presentation.objects[i].id, &ctx->objects);
546			if (!object) {
547			// Missing object. Should only happen with damaged streams.
548			av_log(avctx, AV_LOG_ERROR, "Invalid object id %d\n",
549			ctx->presentation.objects[i].id);
550			if (avctx->err_recognition & AV_EF_EXPLODE) {
551			avsubtitle_free(sub);
552			return AVERROR_INVALIDDATA;
553			}
554			// Leaves rect empty with 0 width and height.
555			continue;
556			}
557			if (ctx->presentation.objects[i].composition_flag & 0x40)
558			sub->rects[i]->flags \|= AV_SUBTITLE_FLAG_FORCED;
559
560			sub->rects[i]->x = ctx->presentation.objects[i].x;
561			sub->rects[i]->y = ctx->presentation.objects[i].y;
562
563			if (object->rle) {
564			sub->rects[i]->w = object->w;
565			sub->rects[i]->h = object->h;
566
567			sub->rects[i]->linesize[0] = object->w;
568
569			if (object->rle_remaining_len) {
570			av_log(avctx, AV_LOG_ERROR, "RLE data length %u is %u bytes shorter than expected\n",
571			object->rle_data_len, object->rle_remaining_len);
572			if (avctx->err_recognition & AV_EF_EXPLODE) {
573			avsubtitle_free(sub);
574			return AVERROR_INVALIDDATA;
575			}
576			}
577			ret = decode_rle(avctx, sub->rects[i], object->rle, object->rle_data_len);
578			if (ret < 0) {
579			if ((avctx->err_recognition & AV_EF_EXPLODE) \|\|
580			ret == AVERROR(ENOMEM)) {
581			avsubtitle_free(sub);
582			return ret;
583			}
584			sub->rects[i]->w = 0;
585			sub->rects[i]->h = 0;
586			continue;
587			}
588			}
589			/* Allocate memory for colors */
590			sub->rects[i]->nb_colors = 256;
591			sub->rects[i]->data[1] = av_mallocz(AVPALETTE_SIZE);
592			if (!sub->rects[i]->data[1]) {
593			avsubtitle_free(sub);
594			return AVERROR(ENOMEM);
595			}
596
597			if (!ctx->forced_subs_only \|\| ctx->presentation.objects[i].composition_flag & 0x40)
598			memcpy(sub->rects[i]->data[1], palette->clut, sub->rects[i]->nb_colors * sizeof(uint32_t));
599
600			#if FF_API_AVPICTURE
601			FF_DISABLE_DEPRECATION_WARNINGS
602			{
603			AVSubtitleRect *rect;
604			int j;
605			rect = sub->rects[i];
606			for (j = 0; j < 4; j++) {
607			rect->pict.data[j] = rect->data[j];
608			rect->pict.linesize[j] = rect->linesize[j];
609			}
610			}
611			FF_ENABLE_DEPRECATION_WARNINGS
612			#endif
613			}
614			return 1;
615			}
616
617			static int decode(AVCodecContext avctx, void data, int *data_size,
618			AVPacket *avpkt)
619			{
620			const uint8_t *buf = avpkt->data;
621			int buf_size = avpkt->size;
622
623			const uint8_t *buf_end;
624			uint8_t segment_type;
625			int segment_length;
626			int i, ret;
627
628			ff_dlog(avctx, "PGS sub packet:\n");
629
630			for (i = 0; i < buf_size; i++) {
631			ff_dlog(avctx, "%02x ", buf[i]);
632			if (i % 16 == 15)
633			ff_dlog(avctx, "\n");
634			}
635
636			if (i & 15)
637			ff_dlog(avctx, "\n");
638
639			*data_size = 0;
640
641			/* Ensure that we have received at a least a segment code and segment length */
642			if (buf_size < 3)
643			return -1;
644
645			buf_end = buf + buf_size;
646
647			/* Step through buffer to identify segments */
648			while (buf < buf_end) {
649			segment_type = bytestream_get_byte(&buf);
650			segment_length = bytestream_get_be16(&buf);
651
652			ff_dlog(avctx, "Segment Length %d, Segment Type %x\n", segment_length, segment_type);
653
654			if (segment_type != DISPLAY_SEGMENT && segment_length > buf_end - buf)
655			break;
656
657			ret = 0;
658			switch (segment_type) {
659			case PALETTE_SEGMENT:
660			ret = parse_palette_segment(avctx, buf, segment_length);
661			break;
662			case OBJECT_SEGMENT:
663			ret = parse_object_segment(avctx, buf, segment_length);
664			break;
665			case PRESENTATION_SEGMENT:
666			ret = parse_presentation_segment(avctx, buf, segment_length, ((AVSubtitle*)(data))->pts);
667			break;
668			case WINDOW_SEGMENT:
669			/*
670			* Window Segment Structure (No new information provided):
671			* 2 bytes: Unknown,
672			* 2 bytes: X position of subtitle,
673			* 2 bytes: Y position of subtitle,
674			* 2 bytes: Width of subtitle,
675			* 2 bytes: Height of subtitle.
676			*/
677			break;
678			case DISPLAY_SEGMENT:
679			if (*data_size) {
680			av_log(avctx, AV_LOG_ERROR, "Duplicate display segment\n");
681			ret = AVERROR_INVALIDDATA;
682			break;
683			}
684			ret = display_end_segment(avctx, data, buf, segment_length);
685			if (ret >= 0)
686			*data_size = ret;
687			break;
688			default:
689			av_log(avctx, AV_LOG_ERROR, "Unknown subtitle segment type 0x%x, length %d\n",
690			segment_type, segment_length);
691			ret = AVERROR_INVALIDDATA;
692			break;
693			}
694			if (ret < 0 && (avctx->err_recognition & AV_EF_EXPLODE))
695			return ret;
696
697			buf += segment_length;
698			}
699
700			return buf_size;
701			}
702
703			#define OFFSET(x) offsetof(PGSSubContext, x)
704			#define SD AV_OPT_FLAG_SUBTITLE_PARAM \| AV_OPT_FLAG_DECODING_PARAM
705			static const AVOption options[] = {
706			{"forced_subs_only", "Only show forced subtitles", OFFSET(forced_subs_only), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, SD},
707			{ NULL },
708			};
709
710			static const AVClass pgsdec_class = {
711			.class_name = "PGS subtitle decoder",
712			.item_name = av_default_item_name,
713			.option = options,
714			.version = LIBAVUTIL_VERSION_INT,
715			};
716
717			AVCodec ff_pgssub_decoder = {
718			.name = "pgssub",
719			.long_name = NULL_IF_CONFIG_SMALL("HDMV Presentation Graphic Stream subtitles"),
720			.type = AVMEDIA_TYPE_SUBTITLE,
721			.id = AV_CODEC_ID_HDMV_PGS_SUBTITLE,
722			.priv_data_size = sizeof(PGSSubContext),
723			.init = init_decoder,
724			.close = close_decoder,
725			.decode = decode,
726			.priv_class = &pgsdec_class,
727			};