Add support for writing sBIT chunks, which mark the significant
bit depth of the PNG file. This obtains the metadata using the field
bits_per_raw_sample of AVCodecContext.
Signed-off-by: Leo Izen <leo.i...@gmail.com>
---
libavcodec/pngenc.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/libavcodec/pngenc.c b/libavcodec/pngenc.c
index 2393161c3b..0961125f0a 100644
--- a/libavcodec/pngenc.c
+++ b/libavcodec/pngenc.c
@@ -432,6 +432,13 @@ 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) {
+ size_t len = s->color_type == 0 ? 1 : s->color_type == 2 ||
s->color_type == 3 ? 3 :
+ s->color_type == 4 ? 2 : 4;
+ memset(s->buf, avctx->bits_per_raw_sample, len);
+ png_write_chunk(&s->bytestream, MKTAG('s', 'B', 'I', 'T'), s->buf,
len);
+ }
+
side_data = av_frame_get_side_data(pict, AV_FRAME_DATA_ICC_PROFILE);
if ((ret = png_write_iccp(s, side_data)))
return ret;
--
2.39.1
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
To unsubscribe, visit link above, or email
ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
