Paul B Mahol: > On Tue, Sep 15, 2020 at 09:39:56AM +0200, Andreas Rheinhardt wrote: >> The Musepack decoder uses static VLC tables to parse the bitstream. >> There are 14 different quant tables VLCs and each of them has a varying >> number of codes. The maximum number is 63, the average number is 25.3. >> Up until now, the array containing the raw data was of type >> uint16_t [7][2][64 * 2] (the 14 tables come in pairs of two, hence [7][2] >> instead of [14]) and from this it follows that there were large gaps in >> said array. This commit changes this by making it a continuous array >> instead. Doing so saves about 2KB. >> >> Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@gmail.com> >> --- >> libavcodec/mpc7.c | 17 ++++++---- >> libavcodec/mpc7data.h | 76 +++++++++++++------------------------------ >> 2 files changed, 32 insertions(+), 61 deletions(-) > > Should be fine if there is full coverage of code with samples covering those > vlcs. > This code is covered by the musepack7 FATE-test. I just added a few counters to it in order to check whether all VLC tables are used. They indeed are: Counter for quant[0][0]: 1478 Counter for quant[0][1]: 2021 Counter for quant[1][0]: 2628 Counter for quant[1][1]: 3500 Counter for quant[2][0]: 1061 Counter for quant[2][1]: 2355 Counter for quant[3][0]: 367 Counter for quant[3][1]: 1048 Counter for quant[4][0]: 598 Counter for quant[4][1]: 1000 Counter for quant[5][0]: 274 Counter for quant[5][1]: 771 Counter for quant[6][0]: 229 Counter for quant[6][1]: 232
Just to be sure I have also calculated the CRCs (AV_CRC_32_IEEE) of the tables. They are unchanged: CRC for quant table 0 0 3BDAC345 CRC for quant table 0 1 F97ACD5D CRC for quant table 1 0 2EBC08F1 CRC for quant table 1 1 FA19B798 CRC for quant table 2 0 16C9A42B CRC for quant table 2 1 B3DF7046 CRC for quant table 3 0 D4162F07 CRC for quant table 3 1 DA23BC68 CRC for quant table 4 0 16D7D50F CRC for quant table 4 1 433F7CB CRC for quant table 5 0 2511392D CRC for quant table 5 1 60C43D91 CRC for quant table 6 0 31C9B671 CRC for quant table 6 1 563EFA5D I have therefore pushed this and the other musepack patch; I have also incorporated a fix for 1e40dc920a838e35f1483b20bfcd417437e68741 in the latter (the topic fits). - Andreas _______________________________________________ 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".
