ffmpeg | branch: master | Michael Niedermayer <mich...@niedermayer.cc> | Wed Mar 5 02:21:03 2025 +0100| [1bce40cb73fffd9d1fb6e118d71ac8999cded808] | committer: Michael Niedermayer
avcodec/ffv1: Use dual run coder for fltmap This improves compression by 0.1% overall and 44% for the changed table I tried several other things but so far this is the best compromise between complexity and compression This can also be extended to 32 and 64bit floats Sponsored-by: Sovereign Tech Fund Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=1bce40cb73fffd9d1fb6e118d71ac8999cded808 --- libavcodec/ffv1dec_template.c | 23 ++++++++++++++++++----- libavcodec/ffv1enc_template.c | 17 ++++++++++++++--- 2 files changed, 32 insertions(+), 8 deletions(-) diff --git a/libavcodec/ffv1dec_template.c b/libavcodec/ffv1dec_template.c index 2769775c36..01e61e1ae8 100644 --- a/libavcodec/ffv1dec_template.c +++ b/libavcodec/ffv1dec_template.c @@ -159,12 +159,25 @@ static int RENAME(decode_rgb_frame)(FFV1Context *f, FFV1SliceContext *sc, for (int p= 0; p<3 + transparency; p++) { int j = 0; int lu = 0; - uint8_t state[2] = {128, 128}; + uint8_t state[2][32]; + memset(state, 128, sizeof(state)); + for (int i= 0; i<65536; i++) { - int u = get_rac(&sc->c, state + lu); - sc->fltmap[p][j] = i ^ ((i&0x8000) ? 0 : 0x7FFF); - j+= u; - lu = u; + int run = get_symbol_inline(&sc->c, state[lu], 0); + if (run > 65536U - i) + return AVERROR_INVALIDDATA; + if (lu) { + lu ^= !run; + while (run--) { + sc->fltmap[p][j++] = i ^ ((i&0x8000) ? 0 : 0x7FFF); + i++; + } + } else { + i += run; + if (i != 65536) + sc->fltmap[p][j++] = i ^ ((i&0x8000) ? 0 : 0x7FFF); + lu ^= !run; + } } } } diff --git a/libavcodec/ffv1enc_template.c b/libavcodec/ffv1enc_template.c index 4c7cd2e647..af3354497a 100644 --- a/libavcodec/ffv1enc_template.c +++ b/libavcodec/ffv1enc_template.c @@ -177,15 +177,26 @@ static int RENAME(encode_rgb_frame)(FFV1Context *f, FFV1SliceContext *sc, for (int p= 0; p<3 + transparency; p++) { int j = 0; int lu = 0; - uint8_t state[2] = {128, 128}; + uint8_t state[2][32]; + int run = 0; + memset(state, 128, sizeof(state)); for (int i= 0; i<65536; i++) { int ri = i ^ ((i&0x8000) ? 0 : 0x7FFF); int u = sc->fltmap[p][ri]; sc->fltmap[p][ri] = j; j+= u; - put_rac(&sc->c, state + lu, u); - lu = u; + + if (lu == u) { + run ++; + } else { + put_symbol_inline(&sc->c, state[lu], run, 0, NULL, NULL); + if (run == 0) + lu = u; + run = 0; + } } + if (run) + put_symbol(&sc->c, state[lu], run, 0); } } _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog To unsubscribe, visit link above, or email ffmpeg-cvslog-requ...@ffmpeg.org with subject "unsubscribe".
