lavc/pngdec: honor skip_frame option

This commit is contained in:
Matthieu Bouron 2015-10-09 15:14:11 +02:00
parent fc460fe618
commit cbe2dfa4e5

View File

@ -1088,6 +1088,13 @@ static int decode_frame_common(AVCodecContext *avctx, PNGDecContext *s,
for (;;) {
length = bytestream2_get_bytes_left(&s->gb);
if (length <= 0) {
if (avctx->codec_id == AV_CODEC_ID_PNG &&
avctx->skip_frame == AVDISCARD_ALL) {
av_frame_set_metadata(p, metadata);
return 0;
}
if (CONFIG_APNG_DECODER && avctx->codec_id == AV_CODEC_ID_APNG && length == 0) {
if (!(s->state & PNG_IDAT))
return 0;
@ -1115,6 +1122,20 @@ static int decode_frame_common(AVCodecContext *avctx, PNGDecContext *s,
((tag >> 8) & 0xff),
((tag >> 16) & 0xff),
((tag >> 24) & 0xff), length);
if (avctx->codec_id == AV_CODEC_ID_PNG &&
avctx->skip_frame == AVDISCARD_ALL) {
switch(tag) {
case MKTAG('I', 'H', 'D', 'R'):
case MKTAG('p', 'H', 'Y', 's'):
case MKTAG('t', 'E', 'X', 't'):
case MKTAG('I', 'D', 'A', 'T'):
break;
default:
goto skip_tag;
}
}
switch (tag) {
case MKTAG('I', 'H', 'D', 'R'):
if ((ret = decode_ihdr_chunk(avctx, s, length)) < 0)
@ -1197,6 +1218,11 @@ skip_tag:
}
}
exit_loop:
if (avctx->codec_id == AV_CODEC_ID_PNG &&
avctx->skip_frame == AVDISCARD_ALL) {
av_frame_set_metadata(p, metadata);
return 0;
}
if (s->bits_per_pixel <= 4)
handle_small_bpp(s, p);
@ -1294,6 +1320,12 @@ static int decode_frame_png(AVCodecContext *avctx,
if ((ret = decode_frame_common(avctx, s, p, avpkt)) < 0)
goto the_end;
if (avctx->skip_frame == AVDISCARD_ALL) {
*got_frame = 0;
ret = bytestream2_tell(&s->gb);
goto the_end;
}
if ((ret = av_frame_ref(data, s->picture.f)) < 0)
return ret;