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  1. /*
  2.  * Bink Audio decoder
  3.  * Copyright (c) 2007-2011 Peter Ross (pross@xvid.org)
  4.  * Copyright (c) 2009 Daniel Verkamp (daniel@drv.nu)
  5.  *
  6.  * This file is part of FFmpeg.
  7.  *
  8.  * FFmpeg is free software; you can redistribute it and/or
  9.  * modify it under the terms of the GNU Lesser General Public
  10.  * License as published by the Free Software Foundation; either
  11.  * version 2.1 of the License, or (at your option) any later version.
  12.  *
  13.  * FFmpeg is distributed in the hope that it will be useful,
  14.  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16.  * Lesser General Public License for more details.
  17.  *
  18.  * You should have received a copy of the GNU Lesser General Public
  19.  * License along with FFmpeg; if not, write to the Free Software
  20.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21.  */
  22.  
  23. /**
  24.  * @file
  25.  * Bink Audio decoder
  26.  *
  27.  * Technical details here:
  28.  *  http://wiki.multimedia.cx/index.php?title=Bink_Audio
  29.  */
  30.  
  31. #include "libavutil/channel_layout.h"
  32. #include "avcodec.h"
  33. #define BITSTREAM_READER_LE
  34. #include "get_bits.h"
  35. #include "dct.h"
  36. #include "rdft.h"
  37. #include "internal.h"
  38. #include "wma_freqs.h"
  39. #include "libavutil/intfloat.h"
  40.  
  41. static float quant_table[96];
  42.  
  43. #define MAX_CHANNELS 2
  44. #define BINK_BLOCK_MAX_SIZE (MAX_CHANNELS << 11)
  45.  
  46. typedef struct BinkAudioContext {
  47.     GetBitContext gb;
  48.     int version_b;          ///< Bink version 'b'
  49.     int first;
  50.     int channels;
  51.     int frame_len;          ///< transform size (samples)
  52.     int overlap_len;        ///< overlap size (samples)
  53.     int block_size;
  54.     int num_bands;
  55.     unsigned int *bands;
  56.     float root;
  57.     DECLARE_ALIGNED(32, FFTSample, coeffs)[BINK_BLOCK_MAX_SIZE];
  58.     float previous[MAX_CHANNELS][BINK_BLOCK_MAX_SIZE / 16];  ///< coeffs from previous audio block
  59.     uint8_t *packet_buffer;
  60.     union {
  61.         RDFTContext rdft;
  62.         DCTContext dct;
  63.     } trans;
  64. } BinkAudioContext;
  65.  
  66.  
  67. static av_cold int decode_init(AVCodecContext *avctx)
  68. {
  69.     BinkAudioContext *s = avctx->priv_data;
  70.     int sample_rate = avctx->sample_rate;
  71.     int sample_rate_half;
  72.     int i;
  73.     int frame_len_bits;
  74.  
  75.     /* determine frame length */
  76.     if (avctx->sample_rate < 22050) {
  77.         frame_len_bits = 9;
  78.     } else if (avctx->sample_rate < 44100) {
  79.         frame_len_bits = 10;
  80.     } else {
  81.         frame_len_bits = 11;
  82.     }
  83.  
  84.     if (avctx->channels < 1 || avctx->channels > MAX_CHANNELS) {
  85.         av_log(avctx, AV_LOG_ERROR, "invalid number of channels: %d\n", avctx->channels);
  86.         return AVERROR_INVALIDDATA;
  87.     }
  88.     avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO :
  89.                                                    AV_CH_LAYOUT_STEREO;
  90.  
  91.     s->version_b = avctx->extradata_size >= 4 && avctx->extradata[3] == 'b';
  92.  
  93.     if (avctx->codec->id == AV_CODEC_ID_BINKAUDIO_RDFT) {
  94.         // audio is already interleaved for the RDFT format variant
  95.         avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
  96.         sample_rate  *= avctx->channels;
  97.         s->channels = 1;
  98.         if (!s->version_b)
  99.             frame_len_bits += av_log2(avctx->channels);
  100.     } else {
  101.         s->channels = avctx->channels;
  102.         avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
  103.     }
  104.  
  105.     s->frame_len     = 1 << frame_len_bits;
  106.     s->overlap_len   = s->frame_len / 16;
  107.     s->block_size    = (s->frame_len - s->overlap_len) * s->channels;
  108.     sample_rate_half = (sample_rate + 1) / 2;
  109.     if (avctx->codec->id == AV_CODEC_ID_BINKAUDIO_RDFT)
  110.         s->root = 2.0 / (sqrt(s->frame_len) * 32768.0);
  111.     else
  112.         s->root = s->frame_len / (sqrt(s->frame_len) * 32768.0);
  113.     for (i = 0; i < 96; i++) {
  114.         /* constant is result of 0.066399999/log10(M_E) */
  115.         quant_table[i] = expf(i * 0.15289164787221953823f) * s->root;
  116.     }
  117.  
  118.     /* calculate number of bands */
  119.     for (s->num_bands = 1; s->num_bands < 25; s->num_bands++)
  120.         if (sample_rate_half <= ff_wma_critical_freqs[s->num_bands - 1])
  121.             break;
  122.  
  123.     s->bands = av_malloc((s->num_bands + 1) * sizeof(*s->bands));
  124.     if (!s->bands)
  125.         return AVERROR(ENOMEM);
  126.  
  127.     /* populate bands data */
  128.     s->bands[0] = 2;
  129.     for (i = 1; i < s->num_bands; i++)
  130.         s->bands[i] = (ff_wma_critical_freqs[i - 1] * s->frame_len / sample_rate_half) & ~1;
  131.     s->bands[s->num_bands] = s->frame_len;
  132.  
  133.     s->first = 1;
  134.  
  135.     if (CONFIG_BINKAUDIO_RDFT_DECODER && avctx->codec->id == AV_CODEC_ID_BINKAUDIO_RDFT)
  136.         ff_rdft_init(&s->trans.rdft, frame_len_bits, DFT_C2R);
  137.     else if (CONFIG_BINKAUDIO_DCT_DECODER)
  138.         ff_dct_init(&s->trans.dct, frame_len_bits, DCT_III);
  139.     else
  140.         return -1;
  141.  
  142.     return 0;
  143. }
  144.  
  145. static float get_float(GetBitContext *gb)
  146. {
  147.     int power = get_bits(gb, 5);
  148.     float f = ldexpf(get_bits_long(gb, 23), power - 23);
  149.     if (get_bits1(gb))
  150.         f = -f;
  151.     return f;
  152. }
  153.  
  154. static const uint8_t rle_length_tab[16] = {
  155.     2, 3, 4, 5, 6, 8, 9, 10, 11, 12, 13, 14, 15, 16, 32, 64
  156. };
  157.  
  158. /**
  159.  * Decode Bink Audio block
  160.  * @param[out] out Output buffer (must contain s->block_size elements)
  161.  * @return 0 on success, negative error code on failure
  162.  */
  163. static int decode_block(BinkAudioContext *s, float **out, int use_dct)
  164. {
  165.     int ch, i, j, k;
  166.     float q, quant[25];
  167.     int width, coeff;
  168.     GetBitContext *gb = &s->gb;
  169.  
  170.     if (use_dct)
  171.         skip_bits(gb, 2);
  172.  
  173.     for (ch = 0; ch < s->channels; ch++) {
  174.         FFTSample *coeffs = out[ch];
  175.  
  176.         if (s->version_b) {
  177.             if (get_bits_left(gb) < 64)
  178.                 return AVERROR_INVALIDDATA;
  179.             coeffs[0] = av_int2float(get_bits_long(gb, 32)) * s->root;
  180.             coeffs[1] = av_int2float(get_bits_long(gb, 32)) * s->root;
  181.         } else {
  182.             if (get_bits_left(gb) < 58)
  183.                 return AVERROR_INVALIDDATA;
  184.             coeffs[0] = get_float(gb) * s->root;
  185.             coeffs[1] = get_float(gb) * s->root;
  186.         }
  187.  
  188.         if (get_bits_left(gb) < s->num_bands * 8)
  189.             return AVERROR_INVALIDDATA;
  190.         for (i = 0; i < s->num_bands; i++) {
  191.             int value = get_bits(gb, 8);
  192.             quant[i]  = quant_table[FFMIN(value, 95)];
  193.         }
  194.  
  195.         k = 0;
  196.         q = quant[0];
  197.  
  198.         // parse coefficients
  199.         i = 2;
  200.         while (i < s->frame_len) {
  201.             if (s->version_b) {
  202.                 j = i + 16;
  203.             } else {
  204.                 int v = get_bits1(gb);
  205.                 if (v) {
  206.                     v = get_bits(gb, 4);
  207.                     j = i + rle_length_tab[v] * 8;
  208.                 } else {
  209.                     j = i + 8;
  210.                 }
  211.             }
  212.  
  213.             j = FFMIN(j, s->frame_len);
  214.  
  215.             width = get_bits(gb, 4);
  216.             if (width == 0) {
  217.                 memset(coeffs + i, 0, (j - i) * sizeof(*coeffs));
  218.                 i = j;
  219.                 while (s->bands[k] < i)
  220.                     q = quant[k++];
  221.             } else {
  222.                 while (i < j) {
  223.                     if (s->bands[k] == i)
  224.                         q = quant[k++];
  225.                     coeff = get_bits(gb, width);
  226.                     if (coeff) {
  227.                         int v;
  228.                         v = get_bits1(gb);
  229.                         if (v)
  230.                             coeffs[i] = -q * coeff;
  231.                         else
  232.                             coeffs[i] =  q * coeff;
  233.                     } else {
  234.                         coeffs[i] = 0.0f;
  235.                     }
  236.                     i++;
  237.                 }
  238.             }
  239.         }
  240.  
  241.         if (CONFIG_BINKAUDIO_DCT_DECODER && use_dct) {
  242.             coeffs[0] /= 0.5;
  243.             s->trans.dct.dct_calc(&s->trans.dct,  coeffs);
  244.         }
  245.         else if (CONFIG_BINKAUDIO_RDFT_DECODER)
  246.             s->trans.rdft.rdft_calc(&s->trans.rdft, coeffs);
  247.     }
  248.  
  249.     for (ch = 0; ch < s->channels; ch++) {
  250.         int j;
  251.         int count = s->overlap_len * s->channels;
  252.         if (!s->first) {
  253.             j = ch;
  254.             for (i = 0; i < s->overlap_len; i++, j += s->channels)
  255.                 out[ch][i] = (s->previous[ch][i] * (count - j) +
  256.                                       out[ch][i] *          j) / count;
  257.         }
  258.         memcpy(s->previous[ch], &out[ch][s->frame_len - s->overlap_len],
  259.                s->overlap_len * sizeof(*s->previous[ch]));
  260.     }
  261.  
  262.     s->first = 0;
  263.  
  264.     return 0;
  265. }
  266.  
  267. static av_cold int decode_end(AVCodecContext *avctx)
  268. {
  269.     BinkAudioContext * s = avctx->priv_data;
  270.     av_freep(&s->bands);
  271.     av_freep(&s->packet_buffer);
  272.     if (CONFIG_BINKAUDIO_RDFT_DECODER && avctx->codec->id == AV_CODEC_ID_BINKAUDIO_RDFT)
  273.         ff_rdft_end(&s->trans.rdft);
  274.     else if (CONFIG_BINKAUDIO_DCT_DECODER)
  275.         ff_dct_end(&s->trans.dct);
  276.  
  277.     return 0;
  278. }
  279.  
  280. static void get_bits_align32(GetBitContext *s)
  281. {
  282.     int n = (-get_bits_count(s)) & 31;
  283.     if (n) skip_bits(s, n);
  284. }
  285.  
  286. static int decode_frame(AVCodecContext *avctx, void *data,
  287.                         int *got_frame_ptr, AVPacket *avpkt)
  288. {
  289.     BinkAudioContext *s = avctx->priv_data;
  290.     AVFrame *frame      = data;
  291.     GetBitContext *gb = &s->gb;
  292.     int ret, consumed = 0;
  293.  
  294.     if (!get_bits_left(gb)) {
  295.         uint8_t *buf;
  296.         /* handle end-of-stream */
  297.         if (!avpkt->size) {
  298.             *got_frame_ptr = 0;
  299.             return 0;
  300.         }
  301.         if (avpkt->size < 4) {
  302.             av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
  303.             return AVERROR_INVALIDDATA;
  304.         }
  305.         buf = av_realloc(s->packet_buffer, avpkt->size + AV_INPUT_BUFFER_PADDING_SIZE);
  306.         if (!buf)
  307.             return AVERROR(ENOMEM);
  308.         memset(buf + avpkt->size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
  309.         s->packet_buffer = buf;
  310.         memcpy(s->packet_buffer, avpkt->data, avpkt->size);
  311.         if ((ret = init_get_bits8(gb, s->packet_buffer, avpkt->size)) < 0)
  312.             return ret;
  313.         consumed = avpkt->size;
  314.  
  315.         /* skip reported size */
  316.         skip_bits_long(gb, 32);
  317.     }
  318.  
  319.     /* get output buffer */
  320.     frame->nb_samples = s->frame_len;
  321.     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
  322.         return ret;
  323.  
  324.     if (decode_block(s, (float **)frame->extended_data,
  325.                      avctx->codec->id == AV_CODEC_ID_BINKAUDIO_DCT)) {
  326.         av_log(avctx, AV_LOG_ERROR, "Incomplete packet\n");
  327.         return AVERROR_INVALIDDATA;
  328.     }
  329.     get_bits_align32(gb);
  330.  
  331.     frame->nb_samples = s->block_size / avctx->channels;
  332.     *got_frame_ptr    = 1;
  333.  
  334.     return consumed;
  335. }
  336.  
  337. AVCodec ff_binkaudio_rdft_decoder = {
  338.     .name           = "binkaudio_rdft",
  339.     .long_name      = NULL_IF_CONFIG_SMALL("Bink Audio (RDFT)"),
  340.     .type           = AVMEDIA_TYPE_AUDIO,
  341.     .id             = AV_CODEC_ID_BINKAUDIO_RDFT,
  342.     .priv_data_size = sizeof(BinkAudioContext),
  343.     .init           = decode_init,
  344.     .close          = decode_end,
  345.     .decode         = decode_frame,
  346.     .capabilities   = AV_CODEC_CAP_DELAY | AV_CODEC_CAP_DR1,
  347. };
  348.  
  349. AVCodec ff_binkaudio_dct_decoder = {
  350.     .name           = "binkaudio_dct",
  351.     .long_name      = NULL_IF_CONFIG_SMALL("Bink Audio (DCT)"),
  352.     .type           = AVMEDIA_TYPE_AUDIO,
  353.     .id             = AV_CODEC_ID_BINKAUDIO_DCT,
  354.     .priv_data_size = sizeof(BinkAudioContext),
  355.     .init           = decode_init,
  356.     .close          = decode_end,
  357.     .decode         = decode_frame,
  358.     .capabilities   = AV_CODEC_CAP_DELAY | AV_CODEC_CAP_DR1,
  359. };
  360.