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avformat/apngdec: transmit all the chunks between consecutive fcTL ones.

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In order to support multiple IDAT of fdAT chunks following an fcTL one,
transmit all the chunks between two fcTL ones (or between fcTL and IEND
one).

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Benoit Fouet 2014-11-24 16:12:26 +01:00 committed by Michael Niedermayer
parent f41cf2e09e
commit 9e1cfbd38a
1 changed files with 24 additions and 10 deletions
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34
libavformat/apngdec.c
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@ -24,10 +24,6 @@
* APNG demuxer.
* @see https://wiki.mozilla.org/APNG_Specification
* @see http://www.w3.org/TR/PNG
*
* Not supported (yet):
* - streams with chunks other than fcTL / fdAT / IEND after the first fcTL
* - streams with multiple fdAT chunks after an fcTL one
*/
#include "avformat.h"
@ -325,8 +321,6 @@ static int apng_read_packet(AVFormatContext *s, AVPacket *pkt)
* and needed next:
* 4 (length)
* 4 (tag (must be fdAT or IDAT))
*
* TODO: support multiple fdAT following an fcTL
*/
/* if num_play is not 1, then the seekback is already guaranteed */
if (ctx->num_play == 1 && (ret = ffio_ensure_seekback(pb, 46)) < 0)
@ -350,15 +344,35 @@ static int apng_read_packet(AVFormatContext *s, AVPacket *pkt)
tag != MKTAG('I', 'D', 'A', 'T'))
return AVERROR_INVALIDDATA;
if ((ret = avio_seek(pb, -46, SEEK_CUR)) < 0)
return ret;
size = 38 /* fcTL */ + 8 /* len, tag */ + len + 4 /* crc */;
if (size > INT_MAX)
return AVERROR(EINVAL);
if ((ret = av_get_packet(pb, pkt, size)) < 0)
if ((ret = avio_seek(pb, -46, SEEK_CUR)) < 0 ||
(ret = av_append_packet(pb, pkt, size)) < 0)
return ret;
if (ctx->num_play == 1 && (ret = ffio_ensure_seekback(pb, 8)) < 0)
return ret;
len = avio_rb32(pb);
tag = avio_rl32(pb);
while (tag &&
tag != MKTAG('f', 'c', 'T', 'L') &&
tag != MKTAG('I', 'E', 'N', 'D')) {
if (len > 0x7fffffff)
return AVERROR_INVALIDDATA;
if ((ret = avio_seek(pb, -8, SEEK_CUR)) < 0 ||
(ret = av_append_packet(pb, pkt, len + 12)) < 0)
return ret;
if (ctx->num_play == 1 && (ret = ffio_ensure_seekback(pb, 8)) < 0)
return ret;
len = avio_rb32(pb);
tag = avio_rl32(pb);
}
if ((ret = avio_seek(pb, -8, SEEK_CUR)) < 0)
return ret;
if (ctx->is_key_frame)
pkt->flags |= AV_PKT_FLAG_KEY;
return ret;