FFmpeg coverage

GCC Code Coverage Report

Directory:	../../../ffmpeg/		Exec	Total	Coverage
File:	src/libavcodec/gif.c	Lines:	187	253	73.9 %
Date:	2020-09-25 23:16:12	Branches:	109	186	58.6 %


/*
 * 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;
    int buf_size;
    AVFrame *last_frame;
    int flags;
    int image;
    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 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;

    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, 0xf7); /* flags: global clut, 256 entries */
        bytestream_put_byte(bytestream, bcid < 0 ? DEFAULT_TRANSPARENCY_INDEX : bcid); /* background color index */
        bytestream_put_byte(bytestream, aspect);
        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;

    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 : 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) {
        bytestream_put_byte(bytestream, 0x00); /* flags */
    } else {
        unsigned i;
        bytestream_put_byte(bytestream, 1<<7 | 0x7); /* flags */
        for (i = 0; i < AVPALETTE_COUNT; i++) {
            const uint32_t v = palette[i];
            bytestream_put_be24(bytestream, v);
        }
    }

    bytestream_put_byte(bytestream, 0x08);

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

    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);
    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 },
    { 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			int buf_size;
51			AVFrame *last_frame;
52			int flags;
53			int image;
54			uint32_t palette[AVPALETTE_COUNT]; ///< local reference palette for !pal8
55			int palette_loaded;
56			int transparent_index;
57			uint8_t *tmpl; ///< temporary line buffer
58			} GIFContext;
59
60			enum {
61			GF_OFFSETTING = 1<<0,
62			GF_TRANSDIFF = 1<<1,
63			};
64
65		1063	static int is_image_translucent(AVCodecContext *avctx,
66			const uint8_t *buf, const int linesize)
67			{
68		1063	GIFContext *s = avctx->priv_data;
69		1063	int trans = s->transparent_index;
70
71	✓✗	1063	if (trans < 0)
72		1063	return 0;
73
74			for (int y = 0; y < avctx->height; y++) {
75			for (int x = 0; x < avctx->width; x++) {
76			if (buf[x] == trans) {
77			return 1;
78			}
79			}
80			buf += linesize;
81			}
82
83			return 0;
84			}
85
86		39	static int get_palette_transparency_index(const uint32_t *palette)
87			{
88		39	int transparent_color_index = -1;
89		39	unsigned i, smallest_alpha = 0xff;
90
91	✓✓	39	if (!palette)
92		30	return -1;
93
94	✓✓	2313	for (i = 0; i < AVPALETTE_COUNT; i++) {
95		2304	const uint32_t v = palette[i];
96	✓✓	2304	if (v >> 24 < smallest_alpha) {
97		2	smallest_alpha = v >> 24;
98		2	transparent_color_index = i;
99			}
100			}
101	✓✓	9	return smallest_alpha < 128 ? transparent_color_index : -1;
102			}
103
104		1056	static int pick_palette_entry(const uint8_t *buf, int linesize, int w, int h)
105			{
106		1056	int histogram[AVPALETTE_COUNT] = {0};
107			int x, y, i;
108
109	✓✓	33543	for (y = 0; y < h; y++) {
110	✓✓	3190262	for (x = 0; x < w; x++)
111		3157775	histogram[buf[x]]++;
112		32487	buf += linesize;
113			}
114	✓✓	7312	for (i = 0; i < FF_ARRAY_ELEMS(histogram); i++)
115	✓✓	7288	if (!histogram[i])
116		1032	return i;
117		24	return -1;
118			}
119
120			static void gif_crop_translucent(AVCodecContext *avctx,
121			const uint8_t *buf, const int linesize,
122			int width, int height,
123			int x_start, int y_start)
124			{
125			GIFContext *s = avctx->priv_data;
126			int trans = s->transparent_index;
127
128			/* Crop image */
129			if ((s->flags & GF_OFFSETTING) && trans >= 0) {
130			const int w = avctx->width;
131			const int h = avctx->height;
132			int x_end = w - 1,
133			y_end = h - 1;
134
135			// crop top
136			while (*y_start < y_end) {
137			int is_trans = 1;
138			for (int i = 0; i < w; i++) {
139			if (buf[linesize * *y_start + i] != trans) {
140			is_trans = 0;
141			break;
142			}
143			}
144
145			if (!is_trans)
146			break;
147			(*y_start)++;
148			}
149
150			// crop bottom
151			while (y_end > *y_start) {
152			int is_trans = 1;
153			for (int i = 0; i < w; i++) {
154			if (buf[linesize * y_end + i] != trans) {
155			is_trans = 0;
156			break;
157			}
158			}
159			if (!is_trans)
160			break;
161			y_end--;
162			}
163
164			// crop left
165			while (*x_start < x_end) {
166			int is_trans = 1;
167			for (int i = *y_start; i < y_end; i++) {
168			if (buf[linesize * i + *x_start] != trans) {
169			is_trans = 0;
170			break;
171			}
172			}
173			if (!is_trans)
174			break;
175			(*x_start)++;
176			}
177
178			// crop right
179			while (x_end > *x_start) {
180			int is_trans = 1;
181			for (int i = *y_start; i < y_end; i++) {
182			if (buf[linesize * i + x_end] != trans) {
183			is_trans = 0;
184			break;
185			}
186			}
187			if (!is_trans)
188			break;
189			x_end--;
190			}
191
192			height = y_end + 1 - y_start;
193			width = x_end + 1 - x_start;
194			av_log(avctx, AV_LOG_DEBUG,"%dx%d image at pos (%d;%d) [area:%dx%d]\n",
195			width, height, x_start, y_start, avctx->width, avctx->height);
196			}
197			}
198
199		1063	static void gif_crop_opaque(AVCodecContext *avctx,
200			const uint32_t *palette,
201			const uint8_t *buf, const int linesize,
202			int width, int height, int x_start, int y_start)
203			{
204		1063	GIFContext *s = avctx->priv_data;
205
206			/* Crop image */
207	✓✗✓✓ ✓✗	1063	if ((s->flags & GF_OFFSETTING) && s->last_frame && !palette) {
208		1056	const uint8_t *ref = s->last_frame->data[0];
209		1056	const int ref_linesize = s->last_frame->linesize[0];
210		1056	int x_end = avctx->width - 1,
211		1056	y_end = avctx->height - 1;
212
213			/* skip common lines */
214	✓✗	100704	while (*y_start < y_end) {
215	✓✓	100704	if (memcmp(ref + y_startref_linesize, buf + y_startlinesize, *width))
216		1056	break;
217		99648	(*y_start)++;
218			}
219	✓✗	99777	while (y_end > *y_start) {
220	✓✓	99777	if (memcmp(ref + y_endref_linesize, buf + y_endlinesize, *width))
221		1056	break;
222		98721	y_end--;
223			}
224		1056	height = y_end + 1 - y_start;
225
226			/* skip common columns */
227	✓✗	96923	while (*x_start < x_end) {
228		96923	int same_column = 1;
229	✓✓	2498501	for (int y = *y_start; y <= y_end; y++) {
230	✓✓	2402634	if (ref[yref_linesize + x_start] != buf[ylinesize + x_start]) {
231		1056	same_column = 0;
232		1056	break;
233			}
234			}
235	✓✓	96923	if (!same_column)
236		1056	break;
237		95867	(*x_start)++;
238			}
239	✓✗	104460	while (x_end > *x_start) {
240		104460	int same_column = 1;
241	✓✓	2546113	for (int y = *y_start; y <= y_end; y++) {
242	✓✓	2442709	if (ref[yref_linesize + x_end] != buf[ylinesize + x_end]) {
243		1056	same_column = 0;
244		1056	break;
245			}
246			}
247	✓✓	104460	if (!same_column)
248		1056	break;
249		103404	x_end--;
250			}
251		1056	width = x_end + 1 - x_start;
252
253		1056	av_log(avctx, AV_LOG_DEBUG,"%dx%d image at pos (%d;%d) [area:%dx%d]\n",
254			width, height, x_start, y_start, avctx->width, avctx->height);
255			}
256		1063	}
257
258		1063	static int gif_image_write_image(AVCodecContext *avctx,
259			uint8_t *bytestream, uint8_t end,
260			const uint32_t *palette,
261			const uint8_t *buf, const int linesize,
262			AVPacket *pkt)
263			{
264		1063	GIFContext *s = avctx->priv_data;
265		1063	int disposal, len = 0, height = avctx->height, width = avctx->width, x, y;
266		1063	int x_start = 0, y_start = 0, trans = s->transparent_index;
267	✓✗✓✓ ✓✗	1063	int bcid = -1, honor_transparency = (s->flags & GF_TRANSDIFF) && s->last_frame && !palette;
268			const uint8_t *ptr;
269
270	✓✗✗✓	1063	if (!s->image && is_image_translucent(avctx, buf, linesize)) {
271			gif_crop_translucent(avctx, buf, linesize, &width, &height, &x_start, &y_start);
272			honor_transparency = 0;
273			disposal = GCE_DISPOSAL_BACKGROUND;
274			} else {
275		1063	gif_crop_opaque(avctx, palette, buf, linesize, &width, &height, &x_start, &y_start);
276		1063	disposal = GCE_DISPOSAL_INPLACE;
277			}
278
279	✓✗✓✓	1063	if (s->image \|\| !avctx->frame_number) { /* GIF header */
280	✓✓	7	const uint32_t *global_palette = palette ? palette : s->palette;
281		7	const AVRational sar = avctx->sample_aspect_ratio;
282		7	int64_t aspect = 0;
283
284	✗✓✗✗	7	if (sar.num > 0 && sar.den > 0) {
285			aspect = sar.num * 64LL / sar.den - 15;
286			if (aspect < 0 \|\| aspect > 255)
287			aspect = 0;
288			}
289
290		7	bytestream_put_buffer(bytestream, gif89a_sig, sizeof(gif89a_sig));
291		7	bytestream_put_le16(bytestream, avctx->width);
292		7	bytestream_put_le16(bytestream, avctx->height);
293
294		7	bcid = get_palette_transparency_index(global_palette);
295
296		7	bytestream_put_byte(bytestream, 0xf7); /* flags: global clut, 256 entries */
297	✓✓	7	bytestream_put_byte(bytestream, bcid < 0 ? DEFAULT_TRANSPARENCY_INDEX : bcid); /* background color index */
298		7	bytestream_put_byte(bytestream, aspect);
299	✓✓	1799	for (int i = 0; i < 256; i++) {
300		1792	const uint32_t v = global_palette[i] & 0xffffff;
301		1792	bytestream_put_be24(bytestream, v);
302			}
303			}
304
305	✓✓✓✗	1063	if (honor_transparency && trans < 0) {
306		1056	trans = pick_palette_entry(buf + y_start*linesize + x_start,
307			linesize, width, height);
308	✓✓	1056	if (trans < 0) // TODO, patch welcome
309		24	av_log(avctx, AV_LOG_DEBUG, "No available color, can not use transparency\n");
310			}
311
312	✓✓	1063	if (trans < 0)
313		31	honor_transparency = 0;
314
315	✓✓✓✗	1063	bcid = honor_transparency \|\| disposal == GCE_DISPOSAL_BACKGROUND ? trans : get_palette_transparency_index(palette);
316
317			/* graphic control extension */
318		1063	bytestream_put_byte(bytestream, GIF_EXTENSION_INTRODUCER);
319		1063	bytestream_put_byte(bytestream, GIF_GCE_EXT_LABEL);
320		1063	bytestream_put_byte(bytestream, 0x04); /* block size */
321		1063	bytestream_put_byte(bytestream, disposal<<2 \| (bcid >= 0));
322		1063	bytestream_put_le16(bytestream, 5); // default delay
323	✓✓	1063	bytestream_put_byte(bytestream, bcid < 0 ? DEFAULT_TRANSPARENCY_INDEX : bcid);
324		1063	bytestream_put_byte(bytestream, 0x00);
325
326			/* image block */
327		1063	bytestream_put_byte(bytestream, GIF_IMAGE_SEPARATOR);
328		1063	bytestream_put_le16(bytestream, x_start);
329		1063	bytestream_put_le16(bytestream, y_start);
330		1063	bytestream_put_le16(bytestream, width);
331		1063	bytestream_put_le16(bytestream, height);
332
333	✓✓	1063	if (!palette) {
334		1062	bytestream_put_byte(bytestream, 0x00); /* flags */
335			} else {
336			unsigned i;
337		1	bytestream_put_byte(bytestream, 1<<7 \| 0x7); /* flags */
338	✓✓	257	for (i = 0; i < AVPALETTE_COUNT; i++) {
339		256	const uint32_t v = palette[i];
340		256	bytestream_put_be24(bytestream, v);
341			}
342			}
343
344		1063	bytestream_put_byte(bytestream, 0x08);
345
346		1063	ff_lzw_encode_init(s->lzw, s->buf, s->buf_size,
347			12, FF_LZW_GIF, 1);
348
349		1063	ptr = buf + y_start*linesize + x_start;
350	✓✓	1063	if (honor_transparency) {
351		1032	const int ref_linesize = s->last_frame->linesize[0];
352		1032	const uint8_t ref = s->last_frame->data[0] + y_startref_linesize + x_start;
353
354	✓✓	26607	for (y = 0; y < height; y++) {
355		25575	memcpy(s->tmpl, ptr, width);
356	✓✓	750326	for (x = 0; x < width; x++)
357	✓✓	724751	if (ref[x] == ptr[x])
358		367271	s->tmpl[x] = trans;
359		25575	len += ff_lzw_encode(s->lzw, s->tmpl, width);
360		25575	ptr += linesize;
361		25575	ref += ref_linesize;
362			}
363			} else {
364	✓✓	8533	for (y = 0; y < height; y++) {
365		8502	len += ff_lzw_encode(s->lzw, ptr, width);
366		8502	ptr += linesize;
367			}
368			}
369		1063	len += ff_lzw_encode_flush(s->lzw);
370
371		1063	ptr = s->buf;
372	✓✓	10314	while (len > 0) {
373		9251	int size = FFMIN(255, len);
374		9251	bytestream_put_byte(bytestream, size);
375	✗✓	9251	if (end - *bytestream < size)
376			return -1;
377		9251	bytestream_put_buffer(bytestream, ptr, size);
378		9251	ptr += size;
379		9251	len -= size;
380			}
381		1063	bytestream_put_byte(bytestream, 0x00); /* end of image block */
382		1063	return 0;
383			}
384
385		7	static av_cold int gif_encode_init(AVCodecContext *avctx)
386			{
387		7	GIFContext *s = avctx->priv_data;
388
389	✓✗✗✓	7	if (avctx->width > 65535 \|\| avctx->height > 65535) {
390			av_log(avctx, AV_LOG_ERROR, "GIF does not support resolutions above 65535x65535\n");
391			return AVERROR(EINVAL);
392			}
393
394		7	s->transparent_index = -1;
395
396		7	s->lzw = av_mallocz(ff_lzw_encode_state_size);
397		7	s->buf_size = avctx->widthavctx->height2 + 1000;
398		7	s->buf = av_malloc(s->buf_size);
399		7	s->tmpl = av_malloc(avctx->width);
400	✓✗✓✗ ✗✓	7	if (!s->tmpl \|\| !s->buf \|\| !s->lzw)
401			return AVERROR(ENOMEM);
402
403	✓✓	7	if (avpriv_set_systematic_pal2(s->palette, avctx->pix_fmt) < 0)
404	✗✓	1	av_assert0(avctx->pix_fmt == AV_PIX_FMT_PAL8);
405
406		7	return 0;
407			}
408
409		1063	static int gif_encode_frame(AVCodecContext avctx, AVPacket pkt,
410			const AVFrame pict, int got_packet)
411			{
412		1063	GIFContext *s = avctx->priv_data;
413			uint8_t outbuf_ptr, end;
414		1063	const uint32_t *palette = NULL;
415			int ret;
416
417	✗✓	1063	if ((ret = ff_alloc_packet2(avctx, pkt, avctx->widthavctx->height7/5 + AV_INPUT_BUFFER_MIN_SIZE, 0)) < 0)
418			return ret;
419		1063	outbuf_ptr = pkt->data;
420		1063	end = pkt->data + pkt->size;
421
422	✓✓	1063	if (avctx->pix_fmt == AV_PIX_FMT_PAL8) {
423		173	palette = (uint32_t*)pict->data[1];
424
425	✓✓	173	if (!s->palette_loaded) {
426		1	memcpy(s->palette, palette, AVPALETTE_SIZE);
427		1	s->transparent_index = get_palette_transparency_index(palette);
428		1	s->palette_loaded = 1;
429	✓✗	172	} else if (!memcmp(s->palette, palette, AVPALETTE_SIZE)) {
430		172	palette = NULL;
431			}
432			}
433
434		1063	gif_image_write_image(avctx, &outbuf_ptr, end, palette,
435		1063	pict->data[0], pict->linesize[0], pkt);
436	✓✓✓✗	1063	if (!s->last_frame && !s->image) {
437		7	s->last_frame = av_frame_alloc();
438	✗✓	7	if (!s->last_frame)
439			return AVERROR(ENOMEM);
440			}
441
442	✓✗	1063	if (!s->image) {
443		1063	av_frame_unref(s->last_frame);
444		1063	ret = av_frame_ref(s->last_frame, (AVFrame*)pict);
445	✗✓	1063	if (ret < 0)
446			return ret;
447			}
448
449		1063	pkt->size = outbuf_ptr - pkt->data;
450	✓✗✓✓	1063	if (s->image \|\| !avctx->frame_number)
451		7	pkt->flags \|= AV_PKT_FLAG_KEY;
452		1063	*got_packet = 1;
453
454		1063	return 0;
455			}
456
457		7	static int gif_encode_close(AVCodecContext *avctx)
458			{
459		7	GIFContext *s = avctx->priv_data;
460
461		7	av_freep(&s->lzw);
462		7	av_freep(&s->buf);
463		7	s->buf_size = 0;
464		7	av_frame_free(&s->last_frame);
465		7	av_freep(&s->tmpl);
466		7	return 0;
467			}
468
469			#define OFFSET(x) offsetof(GIFContext, x)
470			#define FLAGS AV_OPT_FLAG_VIDEO_PARAM \| AV_OPT_FLAG_ENCODING_PARAM
471			static const AVOption gif_options[] = {
472			{ "gifflags", "set GIF flags", OFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = GF_OFFSETTING\|GF_TRANSDIFF}, 0, INT_MAX, FLAGS, "flags" },
473			{ "offsetting", "enable picture offsetting", 0, AV_OPT_TYPE_CONST, {.i64=GF_OFFSETTING}, INT_MIN, INT_MAX, FLAGS, "flags" },
474			{ "transdiff", "enable transparency detection between frames", 0, AV_OPT_TYPE_CONST, {.i64=GF_TRANSDIFF}, INT_MIN, INT_MAX, FLAGS, "flags" },
475			{ "gifimage", "enable encoding only images per frame", OFFSET(image), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS },
476			{ NULL }
477			};
478
479			static const AVClass gif_class = {
480			.class_name = "GIF encoder",
481			.item_name = av_default_item_name,
482			.option = gif_options,
483			.version = LIBAVUTIL_VERSION_INT,
484			};
485
486			AVCodec ff_gif_encoder = {
487			.name = "gif",
488			.long_name = NULL_IF_CONFIG_SMALL("GIF (Graphics Interchange Format)"),
489			.type = AVMEDIA_TYPE_VIDEO,
490			.id = AV_CODEC_ID_GIF,
491			.priv_data_size = sizeof(GIFContext),
492			.init = gif_encode_init,
493			.encode2 = gif_encode_frame,
494			.close = gif_encode_close,
495			.pix_fmts = (const enum AVPixelFormat[]){
496			AV_PIX_FMT_RGB8, AV_PIX_FMT_BGR8, AV_PIX_FMT_RGB4_BYTE, AV_PIX_FMT_BGR4_BYTE,
497			AV_PIX_FMT_GRAY8, AV_PIX_FMT_PAL8, AV_PIX_FMT_NONE
498			},
499			.priv_class = &gif_class,
500			.caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
501			};