From 355bce51f72eab7b3258da8870f11e61d08b8583 Mon Sep 17 00:00:00 2001 From: Andreas Rheinhardt Date: Thu, 29 Oct 2020 20:21:59 +0100 Subject: [PATCH] avcodec/mpc7: Apply offsets when creating VLCs Signed-off-by: Andreas Rheinhardt --- libavcodec/mpc7.c | 14 +++++++------- libavcodec/mpc7data.h | 4 ++-- 2 files changed, 9 insertions(+), 9 deletions(-) diff --git a/libavcodec/mpc7.c b/libavcodec/mpc7.c index 6e800fdccf..795a28c9b4 100644 --- a/libavcodec/mpc7.c +++ b/libavcodec/mpc7.c @@ -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) { diff --git a/libavcodec/mpc7data.h b/libavcodec/mpc7data.h index b578cbdb27..ee77393fce 100644 --- a/libavcodec/mpc7data.h +++ b/libavcodec/mpc7data.h @@ -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] = {