FFmpeg coverage

GCC Code Coverage Report

Directory:	../../../ffmpeg/		Exec	Total	Coverage
File:	src/libavcodec/gif.c	Lines:	219	289	75.8 %
Date:	2021-04-20 15:25:36	Branches:	131	218	60.1 %


/*
 * Copyright (c) 2000 Fabrice Bellard
 * Copyright (c) 2002 Francois Revol
 * Copyright (c) 2006 Baptiste Coudurier
 * Copyright (c) 2018 Bjorn Roche
 * Copyright (c) 2018 Paul B Mahol
 *
 * first version by Francois Revol <revol@free.fr>
 *
 * 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
 * GIF encoder
 * @see http://www.w3.org/Graphics/GIF/spec-gif89a.txt
 */

#define BITSTREAM_WRITER_LE
#include "libavutil/opt.h"
#include "libavutil/imgutils.h"
#include "avcodec.h"
#include "bytestream.h"
#include "internal.h"
#include "lzw.h"
#include "gif.h"

#include "put_bits.h"

#define DEFAULT_TRANSPARENCY_INDEX 0x1f

typedef struct GIFContext {
    const AVClass *class;
    LZWState *lzw;
    uint8_t *buf;
    uint8_t *shrunk_buf;
    int buf_size;
    AVFrame *last_frame;
    int flags;
    int image;
    int use_global_palette;
    uint32_t palette[AVPALETTE_COUNT];  ///< local reference palette for !pal8
    int palette_loaded;
    int transparent_index;
    uint8_t *tmpl;                      ///< temporary line buffer
} GIFContext;

enum {
    GF_OFFSETTING = 1<<0,
    GF_TRANSDIFF  = 1<<1,
};

static void shrink_palette(const uint32_t *src, uint8_t *map,
                           uint32_t *dst, size_t *palette_count)
{
    size_t colors_seen = 0;

    for (size_t i = 0; i < AVPALETTE_COUNT; i++) {
        int seen = 0;
        for (size_t c = 0; c < colors_seen; c++) {
            if (src[i] == dst[c]) {
                seen = 1;
                break;
            }
        }
        if (!seen) {
            dst[colors_seen] = src[i];
            map[i] = colors_seen;
            colors_seen++;
        }
    }

    *palette_count = colors_seen;
}

static void remap_frame_to_palette(const uint8_t *src, int src_linesize,
                                   uint8_t *dst, int dst_linesize,
                                   int w, int h, uint8_t *map)
{
    for (int i = 0; i < h; i++)
        for (int j = 0; j < w; j++)
            dst[i * dst_linesize + j] = map[src[i * src_linesize + j]];
}

static int is_image_translucent(AVCodecContext *avctx,
                                const uint8_t *buf, const int linesize)
{
    GIFContext *s = avctx->priv_data;
    int trans = s->transparent_index;

    if (trans < 0)
        return 0;

    for (int y = 0; y < avctx->height; y++) {
        for (int x = 0; x < avctx->width; x++) {
            if (buf[x] == trans) {
                return 1;
            }
        }
        buf += linesize;
    }

    return 0;
}

static int get_palette_transparency_index(const uint32_t *palette)
{
    int transparent_color_index = -1;
    unsigned i, smallest_alpha = 0xff;

    if (!palette)
        return -1;

    for (i = 0; i < AVPALETTE_COUNT; i++) {
        const uint32_t v = palette[i];
        if (v >> 24 < smallest_alpha) {
            smallest_alpha = v >> 24;
            transparent_color_index = i;
        }
    }
    return smallest_alpha < 128 ? transparent_color_index : -1;
}

static int pick_palette_entry(const uint8_t *buf, int linesize, int w, int h)
{
    int histogram[AVPALETTE_COUNT] = {0};
    int x, y, i;

    for (y = 0; y < h; y++) {
        for (x = 0; x < w; x++)
            histogram[buf[x]]++;
        buf += linesize;
    }
    for (i = 0; i < FF_ARRAY_ELEMS(histogram); i++)
        if (!histogram[i])
            return i;
    return -1;
}

static void gif_crop_translucent(AVCodecContext *avctx,
                                 const uint8_t *buf, const int linesize,
                                 int *width, int *height,
                                 int *x_start, int *y_start)
{
    GIFContext *s = avctx->priv_data;
    int trans = s->transparent_index;

    /* Crop image */
    if ((s->flags & GF_OFFSETTING) && trans >= 0) {
        const int w = avctx->width;
        const int h = avctx->height;
        int x_end = w - 1,
            y_end = h - 1;

        // crop top
        while (*y_start < y_end) {
            int is_trans = 1;
            for (int i = 0; i < w; i++) {
                if (buf[linesize * *y_start + i] != trans) {
                    is_trans = 0;
                    break;
                }
            }

            if (!is_trans)
                break;
            (*y_start)++;
        }

        // crop bottom
        while (y_end > *y_start) {
            int is_trans = 1;
            for (int i = 0; i < w; i++) {
                if (buf[linesize * y_end + i] != trans) {
                    is_trans = 0;
                    break;
                }
            }
            if (!is_trans)
                break;
            y_end--;
        }

        // crop left
        while (*x_start < x_end) {
            int is_trans = 1;
            for (int i = *y_start; i < y_end; i++) {
                if (buf[linesize * i + *x_start] != trans) {
                    is_trans = 0;
                    break;
                }
            }
            if (!is_trans)
                break;
            (*x_start)++;
        }

        // crop right
        while (x_end > *x_start) {
            int is_trans = 1;
            for (int i = *y_start; i < y_end; i++) {
                if (buf[linesize * i + x_end] != trans) {
                    is_trans = 0;
                    break;
                }
            }
            if (!is_trans)
                break;
            x_end--;
        }

        *height = y_end + 1 - *y_start;
        *width  = x_end + 1 - *x_start;
        av_log(avctx, AV_LOG_DEBUG,"%dx%d image at pos (%d;%d) [area:%dx%d]\n",
               *width, *height, *x_start, *y_start, avctx->width, avctx->height);
    }
}

static void gif_crop_opaque(AVCodecContext *avctx,
                            const uint32_t *palette,
                            const uint8_t *buf, const int linesize,
                            int *width, int *height, int *x_start, int *y_start)
{
    GIFContext *s = avctx->priv_data;

    /* Crop image */
    if ((s->flags & GF_OFFSETTING) && s->last_frame && !palette) {
        const uint8_t *ref = s->last_frame->data[0];
        const int ref_linesize = s->last_frame->linesize[0];
        int x_end = avctx->width  - 1,
            y_end = avctx->height - 1;

        /* skip common lines */
        while (*y_start < y_end) {
            if (memcmp(ref + *y_start*ref_linesize, buf + *y_start*linesize, *width))
                break;
            (*y_start)++;
        }
        while (y_end > *y_start) {
            if (memcmp(ref + y_end*ref_linesize, buf + y_end*linesize, *width))
                break;
            y_end--;
        }
        *height = y_end + 1 - *y_start;

        /* skip common columns */
        while (*x_start < x_end) {
            int same_column = 1;
            for (int y = *y_start; y <= y_end; y++) {
                if (ref[y*ref_linesize + *x_start] != buf[y*linesize + *x_start]) {
                    same_column = 0;
                    break;
                }
            }
            if (!same_column)
                break;
            (*x_start)++;
        }
        while (x_end > *x_start) {
            int same_column = 1;
            for (int y = *y_start; y <= y_end; y++) {
                if (ref[y*ref_linesize + x_end] != buf[y*linesize + x_end]) {
                    same_column = 0;
                    break;
                }
            }
            if (!same_column)
                break;
            x_end--;
        }
        *width = x_end + 1 - *x_start;

        av_log(avctx, AV_LOG_DEBUG,"%dx%d image at pos (%d;%d) [area:%dx%d]\n",
               *width, *height, *x_start, *y_start, avctx->width, avctx->height);
    }
}

static int gif_image_write_image(AVCodecContext *avctx,
                                 uint8_t **bytestream, uint8_t *end,
                                 const uint32_t *palette,
                                 const uint8_t *buf, const int linesize,
                                 AVPacket *pkt)
{
    GIFContext *s = avctx->priv_data;
    int disposal, len = 0, height = avctx->height, width = avctx->width, x, y;
    int x_start = 0, y_start = 0, trans = s->transparent_index;
    int bcid = -1, honor_transparency = (s->flags & GF_TRANSDIFF) && s->last_frame && !palette;
    const uint8_t *ptr;
    uint32_t shrunk_palette[AVPALETTE_COUNT];
    uint8_t map[AVPALETTE_COUNT] = { 0 };
    size_t shrunk_palette_count = 0;

    /*
     * We memset to 0xff instead of 0x00 so that the transparency detection
     * doesn't pick anything after the palette entries as the transparency
     * index, and because GIF89a requires us to always write a power-of-2
     * number of palette entries.
     */
    memset(shrunk_palette, 0xff, AVPALETTE_SIZE);

    if (!s->image && is_image_translucent(avctx, buf, linesize)) {
        gif_crop_translucent(avctx, buf, linesize, &width, &height, &x_start, &y_start);
        honor_transparency = 0;
        disposal = GCE_DISPOSAL_BACKGROUND;
    } else {
        gif_crop_opaque(avctx, palette, buf, linesize, &width, &height, &x_start, &y_start);
        disposal = GCE_DISPOSAL_INPLACE;
    }

    if (s->image || !avctx->frame_number) { /* GIF header */
        const uint32_t *global_palette = palette ? palette : s->palette;
        const AVRational sar = avctx->sample_aspect_ratio;
        int64_t aspect = 0;

        if (sar.num > 0 && sar.den > 0) {
            aspect = sar.num * 64LL / sar.den - 15;
            if (aspect < 0 || aspect > 255)
                aspect = 0;
        }

        bytestream_put_buffer(bytestream, gif89a_sig, sizeof(gif89a_sig));
        bytestream_put_le16(bytestream, avctx->width);
        bytestream_put_le16(bytestream, avctx->height);

        bcid = get_palette_transparency_index(global_palette);

        bytestream_put_byte(bytestream, ((uint8_t) s->use_global_palette << 7) | 0x70 | (s->use_global_palette ? 7 : 0)); /* flags: global clut, 256 entries */
        bytestream_put_byte(bytestream, bcid < 0 ? DEFAULT_TRANSPARENCY_INDEX : bcid); /* background color index */
        bytestream_put_byte(bytestream, aspect);
        if (s->use_global_palette) {
            for (int i = 0; i < 256; i++) {
                const uint32_t v = global_palette[i] & 0xffffff;
                bytestream_put_be24(bytestream, v);
            }
        }
    }

    if (honor_transparency && trans < 0) {
        trans = pick_palette_entry(buf + y_start*linesize + x_start,
                                   linesize, width, height);
        if (trans < 0) // TODO, patch welcome
            av_log(avctx, AV_LOG_DEBUG, "No available color, can not use transparency\n");
    }

    if (trans < 0)
        honor_transparency = 0;

    if (palette || !s->use_global_palette) {
        const uint32_t *pal = palette ? palette : s->palette;
        shrink_palette(pal, map, shrunk_palette, &shrunk_palette_count);
    }

    bcid = honor_transparency || disposal == GCE_DISPOSAL_BACKGROUND ? trans : get_palette_transparency_index(palette);

    /* graphic control extension */
    bytestream_put_byte(bytestream, GIF_EXTENSION_INTRODUCER);
    bytestream_put_byte(bytestream, GIF_GCE_EXT_LABEL);
    bytestream_put_byte(bytestream, 0x04); /* block size */
    bytestream_put_byte(bytestream, disposal<<2 | (bcid >= 0));
    bytestream_put_le16(bytestream, 5); // default delay
    bytestream_put_byte(bytestream, bcid < 0 ? DEFAULT_TRANSPARENCY_INDEX : (shrunk_palette_count ? map[bcid] : bcid));
    bytestream_put_byte(bytestream, 0x00);

    /* image block */
    bytestream_put_byte(bytestream, GIF_IMAGE_SEPARATOR);
    bytestream_put_le16(bytestream, x_start);
    bytestream_put_le16(bytestream, y_start);
    bytestream_put_le16(bytestream, width);
    bytestream_put_le16(bytestream, height);

    if (palette || !s->use_global_palette) {
        unsigned pow2_count = av_log2(shrunk_palette_count - 1);
        unsigned i;

        bytestream_put_byte(bytestream, 1<<7 | pow2_count); /* flags */
        for (i = 0; i < 1 << (pow2_count + 1); i++) {
            const uint32_t v = shrunk_palette[i];
            bytestream_put_be24(bytestream, v);
        }
    } else {
        bytestream_put_byte(bytestream, 0x00); /* flags */
    }

    bytestream_put_byte(bytestream, 0x08);

    ff_lzw_encode_init(s->lzw, s->buf, s->buf_size,
                       12, FF_LZW_GIF, 1);

    if (shrunk_palette_count) {
        if (!s->shrunk_buf) {
            s->shrunk_buf = av_malloc(avctx->height * linesize);
            if (!s->shrunk_buf) {
                av_log(avctx, AV_LOG_ERROR, "Could not allocated remapped frame buffer.\n");
                return AVERROR(ENOMEM);
            }
        }
        remap_frame_to_palette(buf, linesize, s->shrunk_buf, linesize, avctx->width, avctx->height, map);
        ptr = s->shrunk_buf + y_start*linesize + x_start;
    } else {
        ptr = buf + y_start*linesize + x_start;
    }
    if (honor_transparency) {
        const int ref_linesize = s->last_frame->linesize[0];
        const uint8_t *ref = s->last_frame->data[0] + y_start*ref_linesize + x_start;

        for (y = 0; y < height; y++) {
            memcpy(s->tmpl, ptr, width);
            for (x = 0; x < width; x++)
                if (ref[x] == ptr[x])
                    s->tmpl[x] = trans;
            len += ff_lzw_encode(s->lzw, s->tmpl, width);
            ptr += linesize;
            ref += ref_linesize;
        }
    } else {
        for (y = 0; y < height; y++) {
            len += ff_lzw_encode(s->lzw, ptr, width);
            ptr += linesize;
        }
    }
    len += ff_lzw_encode_flush(s->lzw);

    ptr = s->buf;
    while (len > 0) {
        int size = FFMIN(255, len);
        bytestream_put_byte(bytestream, size);
        if (end - *bytestream < size)
            return -1;
        bytestream_put_buffer(bytestream, ptr, size);
        ptr += size;
        len -= size;
    }
    bytestream_put_byte(bytestream, 0x00); /* end of image block */
    return 0;
}

static av_cold int gif_encode_init(AVCodecContext *avctx)
{
    GIFContext *s = avctx->priv_data;

    if (avctx->width > 65535 || avctx->height > 65535) {
        av_log(avctx, AV_LOG_ERROR, "GIF does not support resolutions above 65535x65535\n");
        return AVERROR(EINVAL);
    }

    s->transparent_index = -1;

    s->lzw = av_mallocz(ff_lzw_encode_state_size);
    s->buf_size = avctx->width*avctx->height*2 + 1000;
    s->buf = av_malloc(s->buf_size);
    s->tmpl = av_malloc(avctx->width);
    if (!s->tmpl || !s->buf || !s->lzw)
        return AVERROR(ENOMEM);

    if (avpriv_set_systematic_pal2(s->palette, avctx->pix_fmt) < 0)
        av_assert0(avctx->pix_fmt == AV_PIX_FMT_PAL8);

    return 0;
}

static int gif_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
                            const AVFrame *pict, int *got_packet)
{
    GIFContext *s = avctx->priv_data;
    uint8_t *outbuf_ptr, *end;
    const uint32_t *palette = NULL;
    int ret;

    if ((ret = ff_alloc_packet2(avctx, pkt, avctx->width*avctx->height*7/5 + AV_INPUT_BUFFER_MIN_SIZE, 0)) < 0)
        return ret;
    outbuf_ptr = pkt->data;
    end        = pkt->data + pkt->size;

    if (avctx->pix_fmt == AV_PIX_FMT_PAL8) {
        palette = (uint32_t*)pict->data[1];

        if (!s->palette_loaded) {
            memcpy(s->palette, palette, AVPALETTE_SIZE);
            s->transparent_index = get_palette_transparency_index(palette);
            s->palette_loaded = 1;
        } else if (!memcmp(s->palette, palette, AVPALETTE_SIZE)) {
            palette = NULL;
        }
    }

    gif_image_write_image(avctx, &outbuf_ptr, end, palette,
                          pict->data[0], pict->linesize[0], pkt);
    if (!s->last_frame && !s->image) {
        s->last_frame = av_frame_alloc();
        if (!s->last_frame)
            return AVERROR(ENOMEM);
    }

    if (!s->image) {
        av_frame_unref(s->last_frame);
        ret = av_frame_ref(s->last_frame, (AVFrame*)pict);
        if (ret < 0)
            return ret;
    }

    pkt->size   = outbuf_ptr - pkt->data;
    if (s->image || !avctx->frame_number)
        pkt->flags |= AV_PKT_FLAG_KEY;
    *got_packet = 1;

    return 0;
}

static int gif_encode_close(AVCodecContext *avctx)
{
    GIFContext *s = avctx->priv_data;

    av_freep(&s->lzw);
    av_freep(&s->buf);
    av_freep(&s->shrunk_buf);
    s->buf_size = 0;
    av_frame_free(&s->last_frame);
    av_freep(&s->tmpl);
    return 0;
}

#define OFFSET(x) offsetof(GIFContext, x)
#define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
static const AVOption gif_options[] = {
    { "gifflags", "set GIF flags", OFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = GF_OFFSETTING|GF_TRANSDIFF}, 0, INT_MAX, FLAGS, "flags" },
        { "offsetting", "enable picture offsetting", 0, AV_OPT_TYPE_CONST, {.i64=GF_OFFSETTING}, INT_MIN, INT_MAX, FLAGS, "flags" },
        { "transdiff", "enable transparency detection between frames", 0, AV_OPT_TYPE_CONST, {.i64=GF_TRANSDIFF}, INT_MIN, INT_MAX, FLAGS, "flags" },
    { "gifimage", "enable encoding only images per frame", OFFSET(image), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS },
    { "global_palette", "write a palette to the global gif header where feasible", OFFSET(use_global_palette), AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1, FLAGS },
    { NULL }
};

static const AVClass gif_class = {
    .class_name = "GIF encoder",
    .item_name  = av_default_item_name,
    .option     = gif_options,
    .version    = LIBAVUTIL_VERSION_INT,
};

AVCodec ff_gif_encoder = {
    .name           = "gif",
    .long_name      = NULL_IF_CONFIG_SMALL("GIF (Graphics Interchange Format)"),
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_GIF,
    .priv_data_size = sizeof(GIFContext),
    .init           = gif_encode_init,
    .encode2        = gif_encode_frame,
    .close          = gif_encode_close,
    .pix_fmts       = (const enum AVPixelFormat[]){
        AV_PIX_FMT_RGB8, AV_PIX_FMT_BGR8, AV_PIX_FMT_RGB4_BYTE, AV_PIX_FMT_BGR4_BYTE,
        AV_PIX_FMT_GRAY8, AV_PIX_FMT_PAL8, AV_PIX_FMT_NONE
    },
    .priv_class     = &gif_class,
    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
};


Generated by: GCOVR (Version 4.2)

Line	Branch	Exec	Source
1			/*
2			* Copyright (c) 2000 Fabrice Bellard
3			* Copyright (c) 2002 Francois Revol
4			* Copyright (c) 2006 Baptiste Coudurier
5			* Copyright (c) 2018 Bjorn Roche
6			* Copyright (c) 2018 Paul B Mahol
7			*
8			* first version by Francois Revol <revol@free.fr>
9			*
10			* This file is part of FFmpeg.
11			*
12			* FFmpeg is free software; you can redistribute it and/or
13			* modify it under the terms of the GNU Lesser General Public
14			* License as published by the Free Software Foundation; either
15			* version 2.1 of the License, or (at your option) any later version.
16			*
17			* FFmpeg is distributed in the hope that it will be useful,
18			* but WITHOUT ANY WARRANTY; without even the implied warranty of
19			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20			* Lesser General Public License for more details.
21			*
22			* You should have received a copy of the GNU Lesser General Public
23			* License along with FFmpeg; if not, write to the Free Software
24			* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25			*/
26
27			/**
28			* @file
29			* GIF encoder
30			* @see http://www.w3.org/Graphics/GIF/spec-gif89a.txt
31			*/
32
33			#define BITSTREAM_WRITER_LE
34			#include "libavutil/opt.h"
35			#include "libavutil/imgutils.h"
36			#include "avcodec.h"
37			#include "bytestream.h"
38			#include "internal.h"
39			#include "lzw.h"
40			#include "gif.h"
41
42			#include "put_bits.h"
43
44			#define DEFAULT_TRANSPARENCY_INDEX 0x1f
45
46			typedef struct GIFContext {
47			const AVClass *class;
48			LZWState *lzw;
49			uint8_t *buf;
50			uint8_t *shrunk_buf;
51			int buf_size;
52			AVFrame *last_frame;
53			int flags;
54			int image;
55			int use_global_palette;
56			uint32_t palette[AVPALETTE_COUNT]; ///< local reference palette for !pal8
57			int palette_loaded;
58			int transparent_index;
59			uint8_t *tmpl; ///< temporary line buffer
60			} GIFContext;
61
62			enum {
63			GF_OFFSETTING = 1<<0,
64			GF_TRANSDIFF = 1<<1,
65			};
66
67		1	static void shrink_palette(const uint32_t src, uint8_t map,
68			uint32_t dst, size_t palette_count)
69			{
70		1	size_t colors_seen = 0;
71
72	✓✓	257	for (size_t i = 0; i < AVPALETTE_COUNT; i++) {
73		256	int seen = 0;
74	✓✓	32896	for (size_t c = 0; c < colors_seen; c++) {
75	✗✓	32640	if (src[i] == dst[c]) {
76			seen = 1;
77			break;
78			}
79			}
80	✓✗	256	if (!seen) {
81		256	dst[colors_seen] = src[i];
82		256	map[i] = colors_seen;
83		256	colors_seen++;
84			}
85			}
86
87		1	*palette_count = colors_seen;
88		1	}
89
90		1	static void remap_frame_to_palette(const uint8_t *src, int src_linesize,
91			uint8_t *dst, int dst_linesize,
92			int w, int h, uint8_t *map)
93			{
94	✓✓	218	for (int i = 0; i < h; i++)
95	✓✓	47306	for (int j = 0; j < w; j++)
96		47089	dst[i * dst_linesize + j] = map[src[i * src_linesize + j]];
97		1	}
98
99		1063	static int is_image_translucent(AVCodecContext *avctx,
100			const uint8_t *buf, const int linesize)
101			{
102		1063	GIFContext *s = avctx->priv_data;
103		1063	int trans = s->transparent_index;
104
105	✓✗	1063	if (trans < 0)
106		1063	return 0;
107
108			for (int y = 0; y < avctx->height; y++) {
109			for (int x = 0; x < avctx->width; x++) {
110			if (buf[x] == trans) {
111			return 1;
112			}
113			}
114			buf += linesize;
115			}
116
117			return 0;
118			}
119
120		39	static int get_palette_transparency_index(const uint32_t *palette)
121			{
122		39	int transparent_color_index = -1;
123		39	unsigned i, smallest_alpha = 0xff;
124
125	✓✓	39	if (!palette)
126		30	return -1;
127
128	✓✓	2313	for (i = 0; i < AVPALETTE_COUNT; i++) {
129		2304	const uint32_t v = palette[i];
130	✓✓	2304	if (v >> 24 < smallest_alpha) {
131		2	smallest_alpha = v >> 24;
132		2	transparent_color_index = i;
133			}
134			}
135	✓✓	9	return smallest_alpha < 128 ? transparent_color_index : -1;
136			}
137
138		1056	static int pick_palette_entry(const uint8_t *buf, int linesize, int w, int h)
139			{
140		1056	int histogram[AVPALETTE_COUNT] = {0};
141			int x, y, i;
142
143	✓✓	33543	for (y = 0; y < h; y++) {
144	✓✓	3190262	for (x = 0; x < w; x++)
145		3157775	histogram[buf[x]]++;
146		32487	buf += linesize;
147			}
148	✓✓	7312	for (i = 0; i < FF_ARRAY_ELEMS(histogram); i++)
149	✓✓	7288	if (!histogram[i])
150		1032	return i;
151		24	return -1;
152			}
153
154			static void gif_crop_translucent(AVCodecContext *avctx,
155			const uint8_t *buf, const int linesize,
156			int width, int height,
157			int x_start, int y_start)
158			{
159			GIFContext *s = avctx->priv_data;
160			int trans = s->transparent_index;
161
162			/* Crop image */
163			if ((s->flags & GF_OFFSETTING) && trans >= 0) {
164			const int w = avctx->width;
165			const int h = avctx->height;
166			int x_end = w - 1,
167			y_end = h - 1;
168
169			// crop top
170			while (*y_start < y_end) {
171			int is_trans = 1;
172			for (int i = 0; i < w; i++) {
173			if (buf[linesize * *y_start + i] != trans) {
174			is_trans = 0;
175			break;
176			}
177			}
178
179			if (!is_trans)
180			break;
181			(*y_start)++;
182			}
183
184			// crop bottom
185			while (y_end > *y_start) {
186			int is_trans = 1;
187			for (int i = 0; i < w; i++) {
188			if (buf[linesize * y_end + i] != trans) {
189			is_trans = 0;
190			break;
191			}
192			}
193			if (!is_trans)
194			break;
195			y_end--;
196			}
197
198			// crop left
199			while (*x_start < x_end) {
200			int is_trans = 1;
201			for (int i = *y_start; i < y_end; i++) {
202			if (buf[linesize * i + *x_start] != trans) {
203			is_trans = 0;
204			break;
205			}
206			}
207			if (!is_trans)
208			break;
209			(*x_start)++;
210			}
211
212			// crop right
213			while (x_end > *x_start) {
214			int is_trans = 1;
215			for (int i = *y_start; i < y_end; i++) {
216			if (buf[linesize * i + x_end] != trans) {
217			is_trans = 0;
218			break;
219			}
220			}
221			if (!is_trans)
222			break;
223			x_end--;
224			}
225
226			height = y_end + 1 - y_start;
227			width = x_end + 1 - x_start;
228			av_log(avctx, AV_LOG_DEBUG,"%dx%d image at pos (%d;%d) [area:%dx%d]\n",
229			width, height, x_start, y_start, avctx->width, avctx->height);
230			}
231			}
232
233		1063	static void gif_crop_opaque(AVCodecContext *avctx,
234			const uint32_t *palette,
235			const uint8_t *buf, const int linesize,
236			int width, int height, int x_start, int y_start)
237			{
238		1063	GIFContext *s = avctx->priv_data;
239
240			/* Crop image */
241	✓✗✓✓ ✓✗	1063	if ((s->flags & GF_OFFSETTING) && s->last_frame && !palette) {
242		1056	const uint8_t *ref = s->last_frame->data[0];
243		1056	const int ref_linesize = s->last_frame->linesize[0];
244		1056	int x_end = avctx->width - 1,
245		1056	y_end = avctx->height - 1;
246
247			/* skip common lines */
248	✓✗	100704	while (*y_start < y_end) {
249	✓✓	100704	if (memcmp(ref + y_startref_linesize, buf + y_startlinesize, *width))
250		1056	break;
251		99648	(*y_start)++;
252			}
253	✓✗	99777	while (y_end > *y_start) {
254	✓✓	99777	if (memcmp(ref + y_endref_linesize, buf + y_endlinesize, *width))
255		1056	break;
256		98721	y_end--;
257			}
258		1056	height = y_end + 1 - y_start;
259
260			/* skip common columns */
261	✓✗	96923	while (*x_start < x_end) {
262		96923	int same_column = 1;
263	✓✓	2498501	for (int y = *y_start; y <= y_end; y++) {
264	✓✓	2402634	if (ref[yref_linesize + x_start] != buf[ylinesize + x_start]) {
265		1056	same_column = 0;
266		1056	break;
267			}
268			}
269	✓✓	96923	if (!same_column)
270		1056	break;
271		95867	(*x_start)++;
272			}
273	✓✗	104460	while (x_end > *x_start) {
274		104460	int same_column = 1;
275	✓✓	2546113	for (int y = *y_start; y <= y_end; y++) {
276	✓✓	2442709	if (ref[yref_linesize + x_end] != buf[ylinesize + x_end]) {
277		1056	same_column = 0;
278		1056	break;
279			}
280			}
281	✓✓	104460	if (!same_column)
282		1056	break;
283		103404	x_end--;
284			}
285		1056	width = x_end + 1 - x_start;
286
287		1056	av_log(avctx, AV_LOG_DEBUG,"%dx%d image at pos (%d;%d) [area:%dx%d]\n",
288			width, height, x_start, y_start, avctx->width, avctx->height);
289			}
290		1063	}
291
292		1063	static int gif_image_write_image(AVCodecContext *avctx,
293			uint8_t *bytestream, uint8_t end,
294			const uint32_t *palette,
295			const uint8_t *buf, const int linesize,
296			AVPacket *pkt)
297			{
298		1063	GIFContext *s = avctx->priv_data;
299		1063	int disposal, len = 0, height = avctx->height, width = avctx->width, x, y;
300		1063	int x_start = 0, y_start = 0, trans = s->transparent_index;
301	✓✗✓✓ ✓✗	1063	int bcid = -1, honor_transparency = (s->flags & GF_TRANSDIFF) && s->last_frame && !palette;
302			const uint8_t *ptr;
303			uint32_t shrunk_palette[AVPALETTE_COUNT];
304		1063	uint8_t map[AVPALETTE_COUNT] = { 0 };
305		1063	size_t shrunk_palette_count = 0;
306
307			/*
308			* We memset to 0xff instead of 0x00 so that the transparency detection
309			* doesn't pick anything after the palette entries as the transparency
310			* index, and because GIF89a requires us to always write a power-of-2
311			* number of palette entries.
312			*/
313		1063	memset(shrunk_palette, 0xff, AVPALETTE_SIZE);
314
315	✓✗✗✓	1063	if (!s->image && is_image_translucent(avctx, buf, linesize)) {
316			gif_crop_translucent(avctx, buf, linesize, &width, &height, &x_start, &y_start);
317			honor_transparency = 0;
318			disposal = GCE_DISPOSAL_BACKGROUND;
319			} else {
320		1063	gif_crop_opaque(avctx, palette, buf, linesize, &width, &height, &x_start, &y_start);
321		1063	disposal = GCE_DISPOSAL_INPLACE;
322			}
323
324	✓✗✓✓	1063	if (s->image \|\| !avctx->frame_number) { /* GIF header */
325	✓✓	7	const uint32_t *global_palette = palette ? palette : s->palette;
326		7	const AVRational sar = avctx->sample_aspect_ratio;
327		7	int64_t aspect = 0;
328
329	✗✓✗✗	7	if (sar.num > 0 && sar.den > 0) {
330			aspect = sar.num * 64LL / sar.den - 15;
331			if (aspect < 0 \|\| aspect > 255)
332			aspect = 0;
333			}
334
335		7	bytestream_put_buffer(bytestream, gif89a_sig, sizeof(gif89a_sig));
336		7	bytestream_put_le16(bytestream, avctx->width);
337		7	bytestream_put_le16(bytestream, avctx->height);
338
339		7	bcid = get_palette_transparency_index(global_palette);
340
341	✓✗	7	bytestream_put_byte(bytestream, ((uint8_t) s->use_global_palette << 7) \| 0x70 \| (s->use_global_palette ? 7 : 0)); /* flags: global clut, 256 entries */
342	✓✓	7	bytestream_put_byte(bytestream, bcid < 0 ? DEFAULT_TRANSPARENCY_INDEX : bcid); /* background color index */
343		7	bytestream_put_byte(bytestream, aspect);
344	✓✗	7	if (s->use_global_palette) {
345	✓✓	1799	for (int i = 0; i < 256; i++) {
346		1792	const uint32_t v = global_palette[i] & 0xffffff;
347		1792	bytestream_put_be24(bytestream, v);
348			}
349			}
350			}
351
352	✓✓✓✗	1063	if (honor_transparency && trans < 0) {
353		1056	trans = pick_palette_entry(buf + y_start*linesize + x_start,
354			linesize, width, height);
355	✓✓	1056	if (trans < 0) // TODO, patch welcome
356		24	av_log(avctx, AV_LOG_DEBUG, "No available color, can not use transparency\n");
357			}
358
359	✓✓	1063	if (trans < 0)
360		31	honor_transparency = 0;
361
362	✓✓✗✓	1063	if (palette \|\| !s->use_global_palette) {
363	✗✓	1	const uint32_t *pal = palette ? palette : s->palette;
364		1	shrink_palette(pal, map, shrunk_palette, &shrunk_palette_count);
365			}
366
367	✓✓✓✗	1063	bcid = honor_transparency \|\| disposal == GCE_DISPOSAL_BACKGROUND ? trans : get_palette_transparency_index(palette);
368
369			/* graphic control extension */
370		1063	bytestream_put_byte(bytestream, GIF_EXTENSION_INTRODUCER);
371		1063	bytestream_put_byte(bytestream, GIF_GCE_EXT_LABEL);
372		1063	bytestream_put_byte(bytestream, 0x04); /* block size */
373		1063	bytestream_put_byte(bytestream, disposal<<2 \| (bcid >= 0));
374		1063	bytestream_put_le16(bytestream, 5); // default delay
375	✓✓✗✓	1063	bytestream_put_byte(bytestream, bcid < 0 ? DEFAULT_TRANSPARENCY_INDEX : (shrunk_palette_count ? map[bcid] : bcid));
376		1063	bytestream_put_byte(bytestream, 0x00);
377
378			/* image block */
379		1063	bytestream_put_byte(bytestream, GIF_IMAGE_SEPARATOR);
380		1063	bytestream_put_le16(bytestream, x_start);
381		1063	bytestream_put_le16(bytestream, y_start);
382		1063	bytestream_put_le16(bytestream, width);
383		1063	bytestream_put_le16(bytestream, height);
384
385	✓✓✗✓	1064	if (palette \|\| !s->use_global_palette) {
386		1	unsigned pow2_count = av_log2(shrunk_palette_count - 1);
387			unsigned i;
388
389		1	bytestream_put_byte(bytestream, 1<<7 \| pow2_count); /* flags */
390	✓✓	257	for (i = 0; i < 1 << (pow2_count + 1); i++) {
391		256	const uint32_t v = shrunk_palette[i];
392		256	bytestream_put_be24(bytestream, v);
393			}
394			} else {
395		1062	bytestream_put_byte(bytestream, 0x00); /* flags */
396			}
397
398		1063	bytestream_put_byte(bytestream, 0x08);
399
400		1063	ff_lzw_encode_init(s->lzw, s->buf, s->buf_size,
401			12, FF_LZW_GIF, 1);
402
403	✓✓	1063	if (shrunk_palette_count) {
404	✓✗	1	if (!s->shrunk_buf) {
405		1	s->shrunk_buf = av_malloc(avctx->height * linesize);
406	✗✓	1	if (!s->shrunk_buf) {
407			av_log(avctx, AV_LOG_ERROR, "Could not allocated remapped frame buffer.\n");
408			return AVERROR(ENOMEM);
409			}
410			}
411		1	remap_frame_to_palette(buf, linesize, s->shrunk_buf, linesize, avctx->width, avctx->height, map);
412		1	ptr = s->shrunk_buf + y_start*linesize + x_start;
413			} else {
414		1062	ptr = buf + y_start*linesize + x_start;
415			}
416	✓✓	1063	if (honor_transparency) {
417		1032	const int ref_linesize = s->last_frame->linesize[0];
418		1032	const uint8_t ref = s->last_frame->data[0] + y_startref_linesize + x_start;
419
420	✓✓	26607	for (y = 0; y < height; y++) {
421		25575	memcpy(s->tmpl, ptr, width);
422	✓✓	750326	for (x = 0; x < width; x++)
423	✓✓	724751	if (ref[x] == ptr[x])
424		367271	s->tmpl[x] = trans;
425		25575	len += ff_lzw_encode(s->lzw, s->tmpl, width);
426		25575	ptr += linesize;
427		25575	ref += ref_linesize;
428			}
429			} else {
430	✓✓	8533	for (y = 0; y < height; y++) {
431		8502	len += ff_lzw_encode(s->lzw, ptr, width);
432		8502	ptr += linesize;
433			}
434			}
435		1063	len += ff_lzw_encode_flush(s->lzw);
436
437		1063	ptr = s->buf;
438	✓✓	10314	while (len > 0) {
439		9251	int size = FFMIN(255, len);
440		9251	bytestream_put_byte(bytestream, size);
441	✗✓	9251	if (end - *bytestream < size)
442			return -1;
443		9251	bytestream_put_buffer(bytestream, ptr, size);
444		9251	ptr += size;
445		9251	len -= size;
446			}
447		1063	bytestream_put_byte(bytestream, 0x00); /* end of image block */
448		1063	return 0;
449			}
450
451		7	static av_cold int gif_encode_init(AVCodecContext *avctx)
452			{
453		7	GIFContext *s = avctx->priv_data;
454
455	✓✗✗✓	7	if (avctx->width > 65535 \|\| avctx->height > 65535) {
456			av_log(avctx, AV_LOG_ERROR, "GIF does not support resolutions above 65535x65535\n");
457			return AVERROR(EINVAL);
458			}
459
460		7	s->transparent_index = -1;
461
462		7	s->lzw = av_mallocz(ff_lzw_encode_state_size);
463		7	s->buf_size = avctx->widthavctx->height2 + 1000;
464		7	s->buf = av_malloc(s->buf_size);
465		7	s->tmpl = av_malloc(avctx->width);
466	✓✗✓✗ ✗✓	7	if (!s->tmpl \|\| !s->buf \|\| !s->lzw)
467			return AVERROR(ENOMEM);
468
469	✓✓	7	if (avpriv_set_systematic_pal2(s->palette, avctx->pix_fmt) < 0)
470	✗✓	1	av_assert0(avctx->pix_fmt == AV_PIX_FMT_PAL8);
471
472		7	return 0;
473			}
474
475		1063	static int gif_encode_frame(AVCodecContext avctx, AVPacket pkt,
476			const AVFrame pict, int got_packet)
477			{
478		1063	GIFContext *s = avctx->priv_data;
479			uint8_t outbuf_ptr, end;
480		1063	const uint32_t *palette = NULL;
481			int ret;
482
483	✗✓	1063	if ((ret = ff_alloc_packet2(avctx, pkt, avctx->widthavctx->height7/5 + AV_INPUT_BUFFER_MIN_SIZE, 0)) < 0)
484			return ret;
485		1063	outbuf_ptr = pkt->data;
486		1063	end = pkt->data + pkt->size;
487
488	✓✓	1063	if (avctx->pix_fmt == AV_PIX_FMT_PAL8) {
489		173	palette = (uint32_t*)pict->data[1];
490
491	✓✓	173	if (!s->palette_loaded) {
492		1	memcpy(s->palette, palette, AVPALETTE_SIZE);
493		1	s->transparent_index = get_palette_transparency_index(palette);
494		1	s->palette_loaded = 1;
495	✓✗	172	} else if (!memcmp(s->palette, palette, AVPALETTE_SIZE)) {
496		172	palette = NULL;
497			}
498			}
499
500		1063	gif_image_write_image(avctx, &outbuf_ptr, end, palette,
501		1063	pict->data[0], pict->linesize[0], pkt);
502	✓✓✓✗	1063	if (!s->last_frame && !s->image) {
503		7	s->last_frame = av_frame_alloc();
504	✗✓	7	if (!s->last_frame)
505			return AVERROR(ENOMEM);
506			}
507
508	✓✗	1063	if (!s->image) {
509		1063	av_frame_unref(s->last_frame);
510		1063	ret = av_frame_ref(s->last_frame, (AVFrame*)pict);
511	✗✓	1063	if (ret < 0)
512			return ret;
513			}
514
515		1063	pkt->size = outbuf_ptr - pkt->data;
516	✓✗✓✓	1063	if (s->image \|\| !avctx->frame_number)
517		7	pkt->flags \|= AV_PKT_FLAG_KEY;
518		1063	*got_packet = 1;
519
520		1063	return 0;
521			}
522
523		7	static int gif_encode_close(AVCodecContext *avctx)
524			{
525		7	GIFContext *s = avctx->priv_data;
526
527		7	av_freep(&s->lzw);
528		7	av_freep(&s->buf);
529		7	av_freep(&s->shrunk_buf);
530		7	s->buf_size = 0;
531		7	av_frame_free(&s->last_frame);
532		7	av_freep(&s->tmpl);
533		7	return 0;
534			}
535
536			#define OFFSET(x) offsetof(GIFContext, x)
537			#define FLAGS AV_OPT_FLAG_VIDEO_PARAM \| AV_OPT_FLAG_ENCODING_PARAM
538			static const AVOption gif_options[] = {
539			{ "gifflags", "set GIF flags", OFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = GF_OFFSETTING\|GF_TRANSDIFF}, 0, INT_MAX, FLAGS, "flags" },
540			{ "offsetting", "enable picture offsetting", 0, AV_OPT_TYPE_CONST, {.i64=GF_OFFSETTING}, INT_MIN, INT_MAX, FLAGS, "flags" },
541			{ "transdiff", "enable transparency detection between frames", 0, AV_OPT_TYPE_CONST, {.i64=GF_TRANSDIFF}, INT_MIN, INT_MAX, FLAGS, "flags" },
542			{ "gifimage", "enable encoding only images per frame", OFFSET(image), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS },
543			{ "global_palette", "write a palette to the global gif header where feasible", OFFSET(use_global_palette), AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1, FLAGS },
544			{ NULL }
545			};
546
547			static const AVClass gif_class = {
548			.class_name = "GIF encoder",
549			.item_name = av_default_item_name,
550			.option = gif_options,
551			.version = LIBAVUTIL_VERSION_INT,
552			};
553
554			AVCodec ff_gif_encoder = {
555			.name = "gif",
556			.long_name = NULL_IF_CONFIG_SMALL("GIF (Graphics Interchange Format)"),
557			.type = AVMEDIA_TYPE_VIDEO,
558			.id = AV_CODEC_ID_GIF,
559			.priv_data_size = sizeof(GIFContext),
560			.init = gif_encode_init,
561			.encode2 = gif_encode_frame,
562			.close = gif_encode_close,
563			.pix_fmts = (const enum AVPixelFormat[]){
564			AV_PIX_FMT_RGB8, AV_PIX_FMT_BGR8, AV_PIX_FMT_RGB4_BYTE, AV_PIX_FMT_BGR4_BYTE,
565			AV_PIX_FMT_GRAY8, AV_PIX_FMT_PAL8, AV_PIX_FMT_NONE
566			},
567			.priv_class = &gif_class,
568			.caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
569			};