On 8/31/20, Andreas Rheinhardt <andreas.rheinha...@gmail.com> wrote: > When the MagicYUV decoder builds Huffman tables from an array of code > lengths, it proceeds as follows: First it copies the entries of the > array of lengths into an array of HuffEntries (a struct which contains > a length and a symbol field); it also sets the symbol field in > descending order from nb_elem - 1 to 0, where nb_elem is the common number > of elements of the length and HuffEntry arrays. Then the HuffEntry array > is sorted lexicographically: a > b iff a.len > b.len or a.len == b.len and > a.sym > b.sym. Afterwards the symbols of the so sorted array are > inverted again (i.e. each symbol sym is replaced by nb_elem - sym). > > Yet inverting can easily be avoided altogether: Just modify the order so > that smaller symbols correspond to bigger HuffEntries. This leads to the > same permutation as the current code does and given that the two > inversions just cancel each other out, the result is the same. > > Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@gmail.com> > --- > libavcodec/magicyuv.c | 18 +++++++++--------- > 1 file changed, 9 insertions(+), 9 deletions(-) >
LGTM whole patch set. _______________________________________________ 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".
