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| author | Andreas Rheinhardt <andreas.rheinhardt@gmail.com> | 2020-09-15 05:23:07 +0200 |
|---|---|---|
| committer | Andreas Rheinhardt <andreas.rheinhardt@gmail.com> | 2020-09-15 22:14:43 +0200 |
| commit | 158f7df5e6de8c917c679c639758e9ee1d739900 (patch) | |
| tree | 93988cb9242949ff559f032893fd85ade975268e /libavcodec/mpc7.c | |
| parent | bec4e158596bbb5af0eb2e9582cbc28961e6c068 (diff) | |
| download | ffmpeg-158f7df5e6de8c917c679c639758e9ee1d739900.tar.gz | |
avcodec/mpc7, mpc7data: Avoid gaps in array
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.
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Diffstat (limited to 'libavcodec/mpc7.c')
| -rw-r--r-- | libavcodec/mpc7.c | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/libavcodec/mpc7.c b/libavcodec/mpc7.c index 3c9ef6a600..6482029efc 100644 --- a/libavcodec/mpc7.c +++ b/libavcodec/mpc7.c @@ -38,10 +38,9 @@ static VLC scfi_vlc, dscf_vlc, hdr_vlc, quant_vlc[MPC7_QUANT_VLC_TABLES][2]; -static const uint16_t quant_offsets[MPC7_QUANT_VLC_TABLES*2 + 1] = +static const uint16_t quant_sizes[MPC7_QUANT_VLC_TABLES*2] = { - 0, 512, 1024, 1536, 2052, 2564, 3076, 3588, 4100, 4612, 5124, - 5636, 6164, 6676, 7224 + 512, 512, 512, 516, 512, 512, 512, 512, 512, 512, 512, 528, 512, 548 }; @@ -54,6 +53,8 @@ static av_cold int mpc7_decode_init(AVCodecContext * avctx) static int vlc_initialized = 0; static VLC_TYPE quant_tables[7224][2]; + VLC_TYPE (*quant_table)[2] = quant_tables; + const uint16_t *raw_quant_table = mpc7_quant_vlcs; /* Musepack SV7 is always stereo */ if (avctx->channels != 2) { @@ -103,11 +104,13 @@ static av_cold int mpc7_decode_init(AVCodecContext * avctx) &mpc7_hdr[0], 2, 1, 1 << MPC7_HDR_BITS); for(i = 0; i < MPC7_QUANT_VLC_TABLES; i++){ for(j = 0; j < 2; j++){ - quant_vlc[i][j].table = &quant_tables[quant_offsets[i*2 + j]]; - quant_vlc[i][j].table_allocated = quant_offsets[i*2 + j + 1] - quant_offsets[i*2 + j]; + quant_vlc[i][j].table = quant_table; + quant_vlc[i][j].table_allocated = quant_sizes[i * 2 + j]; + quant_table += quant_sizes[i * 2 + j]; init_vlc(&quant_vlc[i][j], 9, mpc7_quant_vlc_sizes[i], - &mpc7_quant_vlc[i][j][1], 4, 2, - &mpc7_quant_vlc[i][j][0], 4, 2, INIT_VLC_USE_NEW_STATIC); + raw_quant_table + 1, 4, 2, + raw_quant_table, 4, 2, INIT_VLC_USE_NEW_STATIC); + raw_quant_table += 2 * mpc7_quant_vlc_sizes[i]; } } vlc_initialized = 1; |