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avcodec/mpc7: Apply offsets when creating VLCs

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Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
This commit is contained in:
Andreas Rheinhardt 2020-10-29 20:21:59 +01:00
parent 354ba64f40
commit 355bce51f7
2 changed files with 9 additions and 9 deletions
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14
libavcodec/mpc7.c
View file

@ -97,10 +97,10 @@ static av_cold int mpc7_decode_init(AVCodecContext * avctx)
&mpc7_scfi[0], 2, 1, 0, 0, 1 << MPC7_SCFI_BITS);
INIT_VLC_STATIC_FROM_LENGTHS(&dscf_vlc, MPC7_DSCF_BITS, MPC7_DSCF_SIZE,
&mpc7_dscf[1], 2,
&mpc7_dscf[0], 2, 1, 0, 0, 1 << MPC7_DSCF_BITS);
&mpc7_dscf[0], 2, 1, -7, 0, 1 << MPC7_DSCF_BITS);
INIT_VLC_STATIC_FROM_LENGTHS(&hdr_vlc, MPC7_HDR_BITS, MPC7_HDR_SIZE,
&mpc7_hdr[1], 2,
&mpc7_hdr[0], 2, 1, 0, 0, 1 << MPC7_HDR_BITS);
&mpc7_hdr[0], 2, 1, -5, 0, 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_table;
@ -109,7 +109,8 @@ static av_cold int mpc7_decode_init(AVCodecContext * avctx)
ff_init_vlc_from_lengths(&quant_vlc[i][j], 9, mpc7_quant_vlc_sizes[i],
&raw_quant_table[1], 2,
&raw_quant_table[0], 2, 1,
0, INIT_VLC_USE_NEW_STATIC, NULL);
mpc7_quant_vlc_off[i],
INIT_VLC_USE_NEW_STATIC, NULL);
raw_quant_table += 2 * mpc7_quant_vlc_sizes[i];
}
}
@ -151,7 +152,7 @@ static inline void idx_to_quant(MPCContext *c, GetBitContext *gb, int idx, int *
case 3: case 4: case 5: case 6: case 7:
i1 = get_bits1(gb);
for(i = 0; i < SAMPLES_PER_BAND; i++)
*dst++ = get_vlc2(gb, quant_vlc[idx-1][i1].table, 9, 2) - mpc7_quant_vlc_off[idx-1];
*dst++ = get_vlc2(gb, quant_vlc[idx-1][i1].table, 9, 2);
break;
case 8: case 9: case 10: case 11: case 12:
case 13: case 14: case 15: case 16: case 17:
@ -166,7 +167,7 @@ static inline void idx_to_quant(MPCContext *c, GetBitContext *gb, int idx, int *
static int get_scale_idx(GetBitContext *gb, int ref)
{
int t = get_vlc2(gb, dscf_vlc.table, MPC7_DSCF_BITS, 1) - 7;
int t = get_vlc2(gb, dscf_vlc.table, MPC7_DSCF_BITS, 1);
if (t == 8)
return get_bits(gb, 6);
return ref + t;
@ -221,8 +222,7 @@ static int mpc7_decode_frame(AVCodecContext * avctx, void *data,
/* read subband indexes */
for(i = 0; i <= c->maxbands; i++){
for(ch = 0; ch < 2; ch++){
int t = 4;
if(i) t = get_vlc2(&gb, hdr_vlc.table, MPC7_HDR_BITS, 1) - 5;
int t = i ? get_vlc2(&gb, hdr_vlc.table, MPC7_HDR_BITS, 1) : 4;
if(t == 4) bands[i].res[ch] = get_bits(&gb, 4);
else bands[i].res[ch] = bands[i-1].res[ch] + t;
if (bands[i].res[ch] < -1 || bands[i].res[ch] > 17) {

4
libavcodec/mpc7data.h
View file

@ -55,8 +55,8 @@ static const uint8_t mpc7_quant_vlc_sizes[MPC7_QUANT_VLC_TABLES] = {
27, 25, 7, 9, 15, 31, 63
};
static const uint8_t mpc7_quant_vlc_off[MPC7_QUANT_VLC_TABLES] = {
0, 0, 3, 4, 7, 15, 31
static const int8_t mpc7_quant_vlc_off[MPC7_QUANT_VLC_TABLES] = {
0, 0, -3, -4, -7, -15, -31
};
static const uint8_t mpc7_quant_vlcs[177 * 2 * 2] = {