/*
* GIF decoder
- * Copyright (c) 2003 Fabrice Bellard.
- * Copyright (c) 2006 Baptiste Coudurier.
+ * Copyright (c) 2003 Fabrice Bellard
+ * Copyright (c) 2006 Baptiste Coudurier
*
- * This file is part of FFmpeg.
+ * This file is part of Libav.
*
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav 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,
+ * Libav 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
+ * License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
-//#define DEBUG
-
+#include "libavutil/imgutils.h"
#include "avcodec.h"
#include "bytestream.h"
+#include "internal.h"
#include "lzw.h"
#define GCE_DISPOSAL_NONE 0
#define GCE_DISPOSAL_RESTORE 3
typedef struct GifState {
- AVFrame picture;
int screen_width;
int screen_height;
int bits_per_pixel;
int gce_delay;
/* LZW compatible decoder */
- uint8_t *bytestream;
+ GetByteContext gb;
LZWState *lzw;
/* aux buffers */
static const uint8_t gif87a_sig[6] = "GIF87a";
static const uint8_t gif89a_sig[6] = "GIF89a";
-static int gif_read_image(GifState *s)
+static int gif_read_image(GifState *s, AVFrame *frame)
{
int left, top, width, height, bits_per_pixel, code_size, flags;
int is_interleaved, has_local_palette, y, pass, y1, linesize, n, i;
uint8_t *ptr, *spal, *palette, *ptr1;
- left = bytestream_get_le16(&s->bytestream);
- top = bytestream_get_le16(&s->bytestream);
- width = bytestream_get_le16(&s->bytestream);
- height = bytestream_get_le16(&s->bytestream);
- flags = bytestream_get_byte(&s->bytestream);
+ left = bytestream2_get_le16(&s->gb);
+ top = bytestream2_get_le16(&s->gb);
+ width = bytestream2_get_le16(&s->gb);
+ height = bytestream2_get_le16(&s->gb);
+ flags = bytestream2_get_byte(&s->gb);
is_interleaved = flags & 0x40;
has_local_palette = flags & 0x80;
bits_per_pixel = (flags & 0x07) + 1;
-#ifdef DEBUG
- dprintf(s->avctx, "gif: image x=%d y=%d w=%d h=%d\n", left, top, width, height);
-#endif
+
+ ff_dlog(s->avctx, "gif: image x=%d y=%d w=%d h=%d\n", left, top, width, height);
if (has_local_palette) {
- bytestream_get_buffer(&s->bytestream, s->local_palette, 3 * (1 << bits_per_pixel));
+ bytestream2_get_buffer(&s->gb, s->local_palette, 3 * (1 << bits_per_pixel));
palette = s->local_palette;
} else {
palette = s->global_palette;
/* verify that all the image is inside the screen dimensions */
if (left + width > s->screen_width ||
- top + height > s->screen_height)
- return AVERROR(EINVAL);
+ top + height > s->screen_height ||
+ !width || !height) {
+ av_log(s->avctx, AV_LOG_ERROR, "Invalid image dimensions.\n");
+ return AVERROR_INVALIDDATA;
+ }
/* build the palette */
n = (1 << bits_per_pixel);
spal = palette;
for(i = 0; i < n; i++) {
- s->image_palette[i] = (0xff << 24) |
- (spal[0] << 16) | (spal[1] << 8) | (spal[2]);
+ s->image_palette[i] = (0xffu << 24) | AV_RB24(spal);
spal += 3;
}
for(; i < 256; i++)
- s->image_palette[i] = (0xff << 24);
+ s->image_palette[i] = (0xffu << 24);
/* handle transparency */
if (s->transparent_color_index >= 0)
s->image_palette[s->transparent_color_index] = 0;
/* now get the image data */
- code_size = bytestream_get_byte(&s->bytestream);
- //TODO: add proper data size
- ff_lzw_decode_init(s->lzw, code_size, s->bytestream, 0, FF_LZW_GIF);
+ code_size = bytestream2_get_byte(&s->gb);
+ ff_lzw_decode_init(s->lzw, code_size, s->gb.buffer,
+ bytestream2_get_bytes_left(&s->gb), FF_LZW_GIF);
/* read all the image */
- linesize = s->picture.linesize[0];
- ptr1 = s->picture.data[0] + top * linesize + left;
+ linesize = frame->linesize[0];
+ ptr1 = frame->data[0] + top * linesize + left;
ptr = ptr1;
pass = 0;
y1 = 0;
case 1:
y1 += 8;
ptr += linesize * 8;
- if (y1 >= height) {
- y1 = 4;
- if (pass == 0)
- ptr = ptr1 + linesize * 4;
- else
- ptr = ptr1 + linesize * 2;
- pass++;
- }
break;
case 2:
y1 += 4;
ptr += linesize * 4;
- if (y1 >= height) {
- y1 = 1;
- ptr = ptr1 + linesize;
- pass++;
- }
break;
case 3:
y1 += 2;
ptr += linesize * 2;
break;
}
+ while (y1 >= height) {
+ y1 = 4 >> pass;
+ ptr = ptr1 + linesize * y1;
+ pass++;
+ }
} else {
ptr += linesize;
}
}
/* read the garbage data until end marker is found */
ff_lzw_decode_tail(s->lzw);
- s->bytestream = ff_lzw_cur_ptr(s->lzw);
+
+ bytestream2_skip(&s->gb, ff_lzw_size_read(s->lzw));
return 0;
}
int ext_code, ext_len, i, gce_flags, gce_transparent_index;
/* extension */
- ext_code = bytestream_get_byte(&s->bytestream);
- ext_len = bytestream_get_byte(&s->bytestream);
-#ifdef DEBUG
- dprintf(s->avctx, "gif: ext_code=0x%x len=%d\n", ext_code, ext_len);
-#endif
+ ext_code = bytestream2_get_byte(&s->gb);
+ ext_len = bytestream2_get_byte(&s->gb);
+
+ ff_dlog(s->avctx, "gif: ext_code=0x%x len=%d\n", ext_code, ext_len);
+
switch(ext_code) {
case 0xf9:
if (ext_len != 4)
goto discard_ext;
s->transparent_color_index = -1;
- gce_flags = bytestream_get_byte(&s->bytestream);
- s->gce_delay = bytestream_get_le16(&s->bytestream);
- gce_transparent_index = bytestream_get_byte(&s->bytestream);
+ gce_flags = bytestream2_get_byte(&s->gb);
+ s->gce_delay = bytestream2_get_le16(&s->gb);
+ gce_transparent_index = bytestream2_get_byte(&s->gb);
if (gce_flags & 0x01)
s->transparent_color_index = gce_transparent_index;
else
s->transparent_color_index = -1;
s->gce_disposal = (gce_flags >> 2) & 0x7;
-#ifdef DEBUG
- dprintf(s->avctx, "gif: gce_flags=%x delay=%d tcolor=%d disposal=%d\n",
+
+ ff_dlog(s->avctx, "gif: gce_flags=%x delay=%d tcolor=%d disposal=%d\n",
gce_flags, s->gce_delay,
s->transparent_color_index, s->gce_disposal);
-#endif
- ext_len = bytestream_get_byte(&s->bytestream);
+
+ ext_len = bytestream2_get_byte(&s->gb);
break;
}
discard_ext:
while (ext_len != 0) {
for (i = 0; i < ext_len; i++)
- bytestream_get_byte(&s->bytestream);
- ext_len = bytestream_get_byte(&s->bytestream);
-#ifdef DEBUG
- dprintf(s->avctx, "gif: ext_len1=%d\n", ext_len);
-#endif
+ bytestream2_get_byte(&s->gb);
+ ext_len = bytestream2_get_byte(&s->gb);
+
+ ff_dlog(s->avctx, "gif: ext_len1=%d\n", ext_len);
}
return 0;
}
int v, n;
int has_global_palette;
+ if (bytestream2_get_bytes_left(&s->gb) < 13)
+ return AVERROR_INVALIDDATA;
+
/* read gif signature */
- bytestream_get_buffer(&s->bytestream, sig, 6);
+ bytestream2_get_buffer(&s->gb, sig, 6);
if (memcmp(sig, gif87a_sig, 6) != 0 &&
memcmp(sig, gif89a_sig, 6) != 0)
- return -1;
+ return AVERROR_INVALIDDATA;
/* read screen header */
s->transparent_color_index = -1;
- s->screen_width = bytestream_get_le16(&s->bytestream);
- s->screen_height = bytestream_get_le16(&s->bytestream);
+ s->screen_width = bytestream2_get_le16(&s->gb);
+ s->screen_height = bytestream2_get_le16(&s->gb);
if( (unsigned)s->screen_width > 32767
|| (unsigned)s->screen_height > 32767){
av_log(NULL, AV_LOG_ERROR, "picture size too large\n");
- return -1;
+ return AVERROR_INVALIDDATA;
}
- v = bytestream_get_byte(&s->bytestream);
+ v = bytestream2_get_byte(&s->gb);
s->color_resolution = ((v & 0x70) >> 4) + 1;
has_global_palette = (v & 0x80);
s->bits_per_pixel = (v & 0x07) + 1;
- s->background_color_index = bytestream_get_byte(&s->bytestream);
- bytestream_get_byte(&s->bytestream); /* ignored */
-#ifdef DEBUG
- dprintf(s->avctx, "gif: screen_w=%d screen_h=%d bpp=%d global_palette=%d\n",
+ s->background_color_index = bytestream2_get_byte(&s->gb);
+ bytestream2_get_byte(&s->gb); /* ignored */
+
+ ff_dlog(s->avctx, "gif: screen_w=%d screen_h=%d bpp=%d global_palette=%d\n",
s->screen_width, s->screen_height, s->bits_per_pixel,
has_global_palette);
-#endif
+
if (has_global_palette) {
n = 1 << s->bits_per_pixel;
- bytestream_get_buffer(&s->bytestream, s->global_palette, n * 3);
+ if (bytestream2_get_bytes_left(&s->gb) < n * 3)
+ return AVERROR_INVALIDDATA;
+ bytestream2_get_buffer(&s->gb, s->global_palette, n * 3);
}
return 0;
}
-static int gif_parse_next_image(GifState *s)
+static int gif_parse_next_image(GifState *s, AVFrame *frame)
{
- int ret, code;
+ while (bytestream2_get_bytes_left(&s->gb) > 0) {
+ int code = bytestream2_get_byte(&s->gb);
+ int ret;
+
+ ff_dlog(s->avctx, "gif: code=%02x '%c'\n", code, code);
- for (;;) {
- code = bytestream_get_byte(&s->bytestream);
-#ifdef DEBUG
- dprintf(s->avctx, "gif: code=%02x '%c'\n", code, code);
-#endif
switch (code) {
case ',':
- if (gif_read_image(s) < 0)
- return -1;
- ret = 0;
- goto the_end;
- case ';':
- /* end of image */
- ret = -1;
- goto the_end;
+ return gif_read_image(s, frame);
case '!':
- if (gif_read_extension(s) < 0)
- return -1;
+ if ((ret = gif_read_extension(s)) < 0)
+ return ret;
break;
- case EOF:
+ case ';':
+ /* end of image */
default:
- /* error or errneous EOF */
- ret = -1;
- goto the_end;
+ /* error or erroneous EOF */
+ return AVERROR_INVALIDDATA;
}
}
- the_end:
- return ret;
+ return AVERROR_INVALIDDATA;
}
-static int gif_decode_init(AVCodecContext *avctx)
+static av_cold int gif_decode_init(AVCodecContext *avctx)
{
GifState *s = avctx->priv_data;
s->avctx = avctx;
- avcodec_get_frame_defaults(&s->picture);
- avctx->coded_frame= &s->picture;
- s->picture.data[0] = NULL;
ff_lzw_decode_open(&s->lzw);
return 0;
}
-static int gif_decode_frame(AVCodecContext *avctx, void *data, int *data_size, uint8_t *buf, int buf_size)
+static int gif_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
+ AVPacket *avpkt)
{
+ const uint8_t *buf = avpkt->data;
+ int buf_size = avpkt->size;
GifState *s = avctx->priv_data;
AVFrame *picture = data;
int ret;
- s->bytestream = buf;
- if (gif_read_header1(s) < 0)
- return -1;
+ bytestream2_init(&s->gb, buf, buf_size);
+ if ((ret = gif_read_header1(s)) < 0)
+ return ret;
+
+ avctx->pix_fmt = AV_PIX_FMT_PAL8;
- avctx->pix_fmt = PIX_FMT_PAL8;
- if (avcodec_check_dimensions(avctx, s->screen_width, s->screen_height))
- return -1;
- avcodec_set_dimensions(avctx, s->screen_width, s->screen_height);
+ if ((ret = ff_set_dimensions(avctx, s->screen_width, s->screen_height)) < 0)
+ return ret;
- if (s->picture.data[0])
- avctx->release_buffer(avctx, &s->picture);
- if (avctx->get_buffer(avctx, &s->picture) < 0) {
+ if ((ret = ff_get_buffer(avctx, picture, 0)) < 0) {
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
- return -1;
+ return ret;
}
- s->image_palette = (uint32_t *)s->picture.data[1];
- ret = gif_parse_next_image(s);
+ s->image_palette = (uint32_t *)picture->data[1];
+ ret = gif_parse_next_image(s, picture);
if (ret < 0)
return ret;
- *picture = s->picture;
- *data_size = sizeof(AVPicture);
- return 0;
+ *got_frame = 1;
+ return bytestream2_tell(&s->gb);
}
-static int gif_decode_close(AVCodecContext *avctx)
+static av_cold int gif_decode_close(AVCodecContext *avctx)
{
GifState *s = avctx->priv_data;
ff_lzw_decode_close(&s->lzw);
- if(s->picture.data[0])
- avctx->release_buffer(avctx, &s->picture);
return 0;
}
-AVCodec gif_decoder = {
- "gif",
- CODEC_TYPE_VIDEO,
- CODEC_ID_GIF,
- sizeof(GifState),
- gif_decode_init,
- NULL,
- gif_decode_close,
- gif_decode_frame,
+AVCodec ff_gif_decoder = {
+ .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(GifState),
+ .init = gif_decode_init,
+ .close = gif_decode_close,
+ .decode = gif_decode_frame,
+ .capabilities = AV_CODEC_CAP_DR1,
};
projects / ffmpeg / blobdiff