[Libav-user] MJPEG Quantization tables

Виктор Мулин 17sep96 at gmail.com
Mon May 18 14:31:28 EEST 2020


Hello! When using the mjpeg codec to convert an image from bmp to jpg
format, a picture with one quantization table is created. I need two
standard tables described in the jpeg iso / iec 10918-1 T.81 standard in
Appendix K.1 and K.2 to be added to the output image file. I also found
them in the ffmpeg source codes (jpegtables.c -> std_luminance_quant_tbl
and jpegtables.c -> std_chrominance_quant_tbl [url:
https://ffmpeg.org/doxygen/trunk/jpegtables_8c_source.html]. I looked
through the mailing list archive and found old solutions (
https://ffmpeg.org/pipermail/libav-user/2015-July/008318.html), but now the
av_codec_set_chroma_intra_matrix () function is declared depricated. How do
I get what I want? How to set intra_matrix, chroma_intra_matrix and
inter_matrix (in the description they are almost the same)?
P.S .: Sorry, I don't speak English well. I use google translator.
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