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FFmpeg/libavcodec/mpc7.c

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  1. /*

  2.  * Musepack SV7 decoder

  3.  * Copyright (c) 2006 Konstantin Shishkov

  4.  *

  5.  * This file is part of FFmpeg.

  6.  *

  7.  * FFmpeg is free software; you can redistribute it and/or

  8.  * modify it under the terms of the GNU Lesser General Public

  9.  * License as published by the Free Software Foundation; either

  10.  * version 2.1 of the License, or (at your option) any later version.

  11.  *

  12.  * FFmpeg is distributed in the hope that it will be useful,

  13.  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  14.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

  15.  * Lesser General Public License for more details.

  16.  *

  17.  * You should have received a copy of the GNU Lesser General Public

  18.  * License along with FFmpeg; if not, write to the Free Software

  19.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  20.  */

  21. 

  22. /**

  23.  * @file mpc7.c Musepack SV7 decoder

  24.  * MPEG Audio Layer 1/2 -like codec with frames of 1152 samples

  25.  * divided into 32 subbands.

  26.  */

  27. 

  28. #include "libavutil/random.h"

  29. #include "avcodec.h"

  30. #include "bitstream.h"

  31. #include "dsputil.h"

  32. 

  33. #ifdef CONFIG_MPEGAUDIO_HP

  34. #define USE_HIGHPRECISION

  35. #endif

  36. #include "mpegaudio.h"

  37. 

  38. #include "mpc.h"

  39. #include "mpc7data.h"

  40. 

  41. #define BANDS            32

  42. #define SAMPLES_PER_BAND 36

  43. #define MPC_FRAME_SIZE   (BANDS * SAMPLES_PER_BAND)

  44. 

  45. static VLC scfi_vlc, dscf_vlc, hdr_vlc, quant_vlc[MPC7_QUANT_VLC_TABLES][2];

  46. 

  47. static av_cold int mpc7_decode_init(AVCodecContext * avctx)

  48. {

  49.     int i, j;

  50.     MPCContext *c = avctx->priv_data;

  51.     GetBitContext gb;

  52.     uint8_t buf[16];

  53.     static int vlc_initialized = 0;

  54. 

  55.     if(avctx->extradata_size < 16){

  56.         av_log(avctx, AV_LOG_ERROR, "Too small extradata size (%i)!\n", avctx->extradata_size);

  57.         return -1;

  58.     }

  59.     memset(c->oldDSCF, 0, sizeof(c->oldDSCF));

  60.     av_init_random(0xDEADBEEF, &c->rnd);

  61.     dsputil_init(&c->dsp, avctx);

  62.     c->dsp.bswap_buf((uint32_t*)buf, (const uint32_t*)avctx->extradata, 4);

  63.     ff_mpc_init();

  64.     init_get_bits(&gb, buf, 128);

  65. 

  66.     c->IS = get_bits1(&gb);

  67.     c->MSS = get_bits1(&gb);

  68.     c->maxbands = get_bits(&gb, 6);

  69.     if(c->maxbands >= BANDS){

  70.         av_log(avctx, AV_LOG_ERROR, "Too many bands: %i\n", c->maxbands);

  71.         return -1;

  72.     }

  73.     skip_bits(&gb, 88);

  74.     c->gapless = get_bits1(&gb);

  75.     c->lastframelen = get_bits(&gb, 11);

  76.     av_log(avctx, AV_LOG_DEBUG, "IS: %d, MSS: %d, TG: %d, LFL: %d, bands: %d\n",

  77.             c->IS, c->MSS, c->gapless, c->lastframelen, c->maxbands);

  78.     c->frames_to_skip = 0;

  79. 

  80.     if(vlc_initialized) return 0;

  81.     av_log(avctx, AV_LOG_DEBUG, "Initing VLC\n");

  82.     if(init_vlc(&scfi_vlc, MPC7_SCFI_BITS, MPC7_SCFI_SIZE,

  83.                 &mpc7_scfi[1], 2, 1,

  84.                 &mpc7_scfi[0], 2, 1, INIT_VLC_USE_STATIC)){

  85.         av_log(avctx, AV_LOG_ERROR, "Cannot init SCFI VLC\n");

  86.         return -1;

  87.     }

  88.     if(init_vlc(&dscf_vlc, MPC7_DSCF_BITS, MPC7_DSCF_SIZE,

  89.                 &mpc7_dscf[1], 2, 1,

  90.                 &mpc7_dscf[0], 2, 1, INIT_VLC_USE_STATIC)){

  91.         av_log(avctx, AV_LOG_ERROR, "Cannot init DSCF VLC\n");

  92.         return -1;

  93.     }

  94.     if(init_vlc(&hdr_vlc, MPC7_HDR_BITS, MPC7_HDR_SIZE,

  95.                 &mpc7_hdr[1], 2, 1,

  96.                 &mpc7_hdr[0], 2, 1, INIT_VLC_USE_STATIC)){

  97.         av_log(avctx, AV_LOG_ERROR, "Cannot init HDR VLC\n");

  98.         return -1;

  99.     }

  100.     for(i = 0; i < MPC7_QUANT_VLC_TABLES; i++){

  101.         for(j = 0; j < 2; j++){

  102.             if(init_vlc(&quant_vlc[i][j], 9, mpc7_quant_vlc_sizes[i],

  103.                         &mpc7_quant_vlc[i][j][1], 4, 2,

  104.                         &mpc7_quant_vlc[i][j][0], 4, 2, INIT_VLC_USE_STATIC)){

  105.                 av_log(avctx, AV_LOG_ERROR, "Cannot init QUANT VLC %i,%i\n",i,j);

  106.                 return -1;

  107.             }

  108.         }

  109.     }

  110.     vlc_initialized = 1;

  111.     return 0;

  112. }

  113. 

  114. /**

  115.  * Fill samples for given subband

  116.  */

  117. static inline void idx_to_quant(MPCContext *c, GetBitContext *gb, int idx, int *dst)

  118. {

  119.     int i, i1, t;

  120.     switch(idx){

  121.     case -1:

  122.         for(i = 0; i < SAMPLES_PER_BAND; i++){

  123.             *dst++ = (av_random(&c->rnd) & 0x3FC) - 510;

  124.         }

  125.         break;

  126.     case 1:

  127.         i1 = get_bits1(gb);

  128.         for(i = 0; i < SAMPLES_PER_BAND/3; i++){

  129.             t = get_vlc2(gb, quant_vlc[0][i1].table, 9, 2);

  130.             *dst++ = mpc7_idx30[t];

  131.             *dst++ = mpc7_idx31[t];

  132.             *dst++ = mpc7_idx32[t];

  133.         }

  134.         break;

  135.     case 2:

  136.         i1 = get_bits1(gb);

  137.         for(i = 0; i < SAMPLES_PER_BAND/2; i++){

  138.             t = get_vlc2(gb, quant_vlc[1][i1].table, 9, 2);

  139.             *dst++ = mpc7_idx50[t];

  140.             *dst++ = mpc7_idx51[t];

  141.         }

  142.         break;

  143.     case  3: case  4: case  5: case  6: case  7:

  144.         i1 = get_bits1(gb);

  145.         for(i = 0; i < SAMPLES_PER_BAND; i++)

  146.             *dst++ = get_vlc2(gb, quant_vlc[idx-1][i1].table, 9, 2) - mpc7_quant_vlc_off[idx-1];

  147.         break;

  148.     case  8: case  9: case 10: case 11: case 12:

  149.     case 13: case 14: case 15: case 16: case 17:

  150.         t = (1 << (idx - 2)) - 1;

  151.         for(i = 0; i < SAMPLES_PER_BAND; i++)

  152.             *dst++ = get_bits(gb, idx - 1) - t;

  153.         break;

  154.     default: // case 0 and -2..-17

  155.         return;

  156.     }

  157. }

  158. 

  159. static int mpc7_decode_frame(AVCodecContext * avctx,

  160.                             void *data, int *data_size,

  161.                             const uint8_t * buf, int buf_size)

  162. {

  163.     MPCContext *c = avctx->priv_data;

  164.     GetBitContext gb;

  165.     uint8_t *bits;

  166.     int i, ch, t;

  167.     int mb = -1;

  168.     Band *bands = c->bands;

  169.     int off;

  170.     int bits_used, bits_avail;

  171. 

  172.     memset(bands, 0, sizeof(bands));

  173.     if(buf_size <= 4){

  174.         av_log(avctx, AV_LOG_ERROR, "Too small buffer passed (%i bytes)\n", buf_size);

  175.     }

  176. 

  177.     bits = av_malloc(((buf_size - 1) & ~3) + FF_INPUT_BUFFER_PADDING_SIZE);

  178.     c->dsp.bswap_buf((uint32_t*)bits, (const uint32_t*)(buf + 4), (buf_size - 4) >> 2);

  179.     init_get_bits(&gb, bits, (buf_size - 4)* 8);

  180.     skip_bits(&gb, buf[0]);

  181. 

  182.     /* read subband indexes */

  183.     for(i = 0; i <= c->maxbands; i++){

  184.         for(ch = 0; ch < 2; ch++){

  185.             if(i) t = get_vlc2(&gb, hdr_vlc.table, MPC7_HDR_BITS, 1) - 5;

  186.             if(!i || (t == 4)) bands[i].res[ch] = get_bits(&gb, 4);

  187.             else bands[i].res[ch] = bands[i-1].res[ch] + t;

  188.         }

  189. 

  190.         if(bands[i].res[0] || bands[i].res[1]){

  191.             mb = i;

  192.             if(c->MSS) bands[i].msf = get_bits1(&gb);

  193.         }

  194.     }

  195.     /* get scale indexes coding method */

  196.     for(i = 0; i <= mb; i++)

  197.         for(ch = 0; ch < 2; ch++)

  198.             if(bands[i].res[ch]) bands[i].scfi[ch] = get_vlc2(&gb, scfi_vlc.table, MPC7_SCFI_BITS, 1);

  199.     /* get scale indexes */

  200.     for(i = 0; i <= mb; i++){

  201.         for(ch = 0; ch < 2; ch++){

  202.             if(bands[i].res[ch]){

  203.                 bands[i].scf_idx[ch][2] = c->oldDSCF[ch][i];

  204.                 t = get_vlc2(&gb, dscf_vlc.table, MPC7_DSCF_BITS, 1) - 7;

  205.                 bands[i].scf_idx[ch][0] = (t == 8) ? get_bits(&gb, 6) : (bands[i].scf_idx[ch][2] + t);

  206.                 switch(bands[i].scfi[ch]){

  207.                 case 0:

  208.                     t = get_vlc2(&gb, dscf_vlc.table, MPC7_DSCF_BITS, 1) - 7;

  209.                     bands[i].scf_idx[ch][1] = (t == 8) ? get_bits(&gb, 6) : (bands[i].scf_idx[ch][0] + t);

  210.                     t = get_vlc2(&gb, dscf_vlc.table, MPC7_DSCF_BITS, 1) - 7;

  211.                     bands[i].scf_idx[ch][2] = (t == 8) ? get_bits(&gb, 6) : (bands[i].scf_idx[ch][1] + t);

  212.                     break;

  213.                 case 1:

  214.                     t = get_vlc2(&gb, dscf_vlc.table, MPC7_DSCF_BITS, 1) - 7;

  215.                     bands[i].scf_idx[ch][1] = (t == 8) ? get_bits(&gb, 6) : (bands[i].scf_idx[ch][0] + t);

  216.                     bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1];

  217.                     break;

  218.                 case 2:

  219.                     bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];

  220.                     t = get_vlc2(&gb, dscf_vlc.table, MPC7_DSCF_BITS, 1) - 7;

  221.                     bands[i].scf_idx[ch][2] = (t == 8) ? get_bits(&gb, 6) : (bands[i].scf_idx[ch][1] + t);

  222.                     break;

  223.                 case 3:

  224.                     bands[i].scf_idx[ch][2] = bands[i].scf_idx[ch][1] = bands[i].scf_idx[ch][0];

  225.                     break;

  226.                 }

  227.                 c->oldDSCF[ch][i] = bands[i].scf_idx[ch][2];

  228.             }

  229.         }

  230.     }

  231.     /* get quantizers */

  232.     memset(c->Q, 0, sizeof(c->Q));

  233.     off = 0;

  234.     for(i = 0; i < BANDS; i++, off += SAMPLES_PER_BAND)

  235.         for(ch = 0; ch < 2; ch++)

  236.             idx_to_quant(c, &gb, bands[i].res[ch], c->Q[ch] + off);

  237. 

  238.     ff_mpc_dequantize_and_synth(c, mb, data);

  239. 

  240.     av_free(bits);

  241. 

  242.     bits_used = get_bits_count(&gb);

  243.     bits_avail = (buf_size - 4) * 8;

  244.     if(!buf[1] && ((bits_avail < bits_used) || (bits_used + 32 <= bits_avail))){

  245.         av_log(NULL,0, "Error decoding frame: used %i of %i bits\n", bits_used, bits_avail);

  246.         return -1;

  247.     }

  248.     if(c->frames_to_skip){

  249.         c->frames_to_skip--;

  250.         *data_size = 0;

  251.         return buf_size;

  252.     }

  253.     *data_size = (buf[1] ? c->lastframelen : MPC_FRAME_SIZE) * 4;

  254. 

  255.     return buf_size;

  256. }

  257. 

  258. static void mpc7_decode_flush(AVCodecContext *avctx)

  259. {

  260.     MPCContext *c = avctx->priv_data;

  261. 

  262.     memset(c->oldDSCF, 0, sizeof(c->oldDSCF));

  263.     c->frames_to_skip = 32;

  264. }

  265. 

  266. AVCodec mpc7_decoder = {

  267.     "mpc7",

  268.     CODEC_TYPE_AUDIO,

  269.     CODEC_ID_MUSEPACK7,

  270.     sizeof(MPCContext),

  271.     mpc7_decode_init,

  272.     NULL,

  273.     NULL,

  274.     mpc7_decode_frame,

  275.     .flush = mpc7_decode_flush,

  276.     .long_name = "Musepack SV7",

  277. };