diff options
| author | Leo Izen <leo.izen@gmail.com> | 2024-07-19 12:04:20 -0400 |
|---|---|---|
| committer | Leo Izen <leo.izen@gmail.com> | 2024-07-30 05:43:36 -0400 |
| commit | 7bb5626fa7754b37932dfa11d497b7101c55291a (patch) | |
| tree | d5a03d9b37d71f883082ecb75d34146905a67fa5 /libavcodec | |
| parent | 825606641b11f3f1f5c5efb0f95501b2c2d34d50 (diff) | |
| download | ffmpeg-7bb5626fa7754b37932dfa11d497b7101c55291a.tar.gz | |
avcodec/pngenc: fix sBIT writing for indexed-color PNGs
We currently write invalid sBIT entries for indexed PNGs, which by PNG
specification[1] must be 3-bytes long. The values also are capped at 8
for indexed-color PNGs, not the palette depth. This patch fixes both of
these issues previously fixed in the decoder, but not the encoder.
[1]: https://www.w3.org/TR/png-3/#11sBIT
Regression since: c125860892e931d9b10f88ace73c91484815c3a8.
Signed-off-by: Leo Izen <leo.izen@gmail.com>
Reported-by: Ramiro Polla: <ramiro.polla@gmail.com>
Diffstat (limited to 'libavcodec')
| -rw-r--r-- | libavcodec/pngenc.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/libavcodec/pngenc.c b/libavcodec/pngenc.c index 7ae16fa2c5..cb79c04e11 100644 --- a/libavcodec/pngenc.c +++ b/libavcodec/pngenc.c @@ -469,8 +469,9 @@ static int encode_headers(AVCodecContext *avctx, const AVFrame *pict) if (png_get_gama(pict->color_trc, s->buf)) png_write_chunk(&s->bytestream, MKTAG('g', 'A', 'M', 'A'), s->buf, 4); - if (avctx->bits_per_raw_sample > 0 && avctx->bits_per_raw_sample < s->bit_depth) { - int len = ff_png_get_nb_channels(s->color_type); + if (avctx->bits_per_raw_sample > 0 && + avctx->bits_per_raw_sample < (s->color_type & PNG_COLOR_MASK_PALETTE ? 8 : s->bit_depth)) { + int len = s->color_type & PNG_COLOR_MASK_PALETTE ? 3 : ff_png_get_nb_channels(s->color_type); memset(s->buf, avctx->bits_per_raw_sample, len); png_write_chunk(&s->bytestream, MKTAG('s', 'B', 'I', 'T'), s->buf, len); } |