LCOV - code coverage report
Current view: top level - libavcodec - ra288.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 74 81 91.4 %
Date: 2017-12-13 10:57:33 Functions: 7 7 100.0 %

          Line data    Source code
       1             : /*
       2             :  * RealAudio 2.0 (28.8K)
       3             :  * Copyright (c) 2003 The FFmpeg project
       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             : #include "libavutil/channel_layout.h"
      23             : #include "libavutil/float_dsp.h"
      24             : #include "libavutil/internal.h"
      25             : 
      26             : #define BITSTREAM_READER_LE
      27             : #include "avcodec.h"
      28             : #include "celp_filters.h"
      29             : #include "get_bits.h"
      30             : #include "internal.h"
      31             : #include "lpc.h"
      32             : #include "ra288.h"
      33             : 
      34             : #define MAX_BACKWARD_FILTER_ORDER  36
      35             : #define MAX_BACKWARD_FILTER_LEN    40
      36             : #define MAX_BACKWARD_FILTER_NONREC 35
      37             : 
      38             : #define RA288_BLOCK_SIZE        5
      39             : #define RA288_BLOCKS_PER_FRAME 32
      40             : 
      41             : typedef struct RA288Context {
      42             :     AVFloatDSPContext *fdsp;
      43             :     DECLARE_ALIGNED(32, float,   sp_lpc)[FFALIGN(36, 16)];   ///< LPC coefficients for speech data (spec: A)
      44             :     DECLARE_ALIGNED(32, float, gain_lpc)[FFALIGN(10, 16)];   ///< LPC coefficients for gain        (spec: GB)
      45             : 
      46             :     /** speech data history                                      (spec: SB).
      47             :      *  Its first 70 coefficients are updated only at backward filtering.
      48             :      */
      49             :     float sp_hist[111];
      50             : 
      51             :     /// speech part of the gain autocorrelation                  (spec: REXP)
      52             :     float sp_rec[37];
      53             : 
      54             :     /** log-gain history                                         (spec: SBLG).
      55             :      *  Its first 28 coefficients are updated only at backward filtering.
      56             :      */
      57             :     float gain_hist[38];
      58             : 
      59             :     /// recursive part of the gain autocorrelation               (spec: REXPLG)
      60             :     float gain_rec[11];
      61             : } RA288Context;
      62             : 
      63           2 : static av_cold int ra288_decode_close(AVCodecContext *avctx)
      64             : {
      65           2 :     RA288Context *ractx = avctx->priv_data;
      66             : 
      67           2 :     av_freep(&ractx->fdsp);
      68             : 
      69           2 :     return 0;
      70             : }
      71             : 
      72           2 : static av_cold int ra288_decode_init(AVCodecContext *avctx)
      73             : {
      74           2 :     RA288Context *ractx = avctx->priv_data;
      75             : 
      76           2 :     avctx->channels       = 1;
      77           2 :     avctx->channel_layout = AV_CH_LAYOUT_MONO;
      78           2 :     avctx->sample_fmt     = AV_SAMPLE_FMT_FLT;
      79             : 
      80           2 :     if (avctx->block_align <= 0) {
      81           0 :         av_log(avctx, AV_LOG_ERROR, "unsupported block align\n");
      82           0 :         return AVERROR_PATCHWELCOME;
      83             :     }
      84             : 
      85           2 :     ractx->fdsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT);
      86           2 :     if (!ractx->fdsp)
      87           0 :         return AVERROR(ENOMEM);
      88             : 
      89           2 :     return 0;
      90             : }
      91             : 
      92       39168 : static void convolve(float *tgt, const float *src, int len, int n)
      93             : {
      94      979200 :     for (; n >= 0; n--)
      95      940032 :         tgt[n] = avpriv_scalarproduct_float_c(src, src - n, len);
      96             : 
      97       39168 : }
      98             : 
      99       78336 : static void decode(RA288Context *ractx, float gain, int cb_coef)
     100             : {
     101             :     int i;
     102             :     double sumsum;
     103             :     float sum, buffer[5];
     104       78336 :     float *block = ractx->sp_hist + 70 + 36; // current block
     105       78336 :     float *gain_block = ractx->gain_hist + 28;
     106             : 
     107       78336 :     memmove(ractx->sp_hist + 70, ractx->sp_hist + 75, 36*sizeof(*block));
     108             : 
     109             :     /* block 46 of G.728 spec */
     110       78336 :     sum = 32.0;
     111      861696 :     for (i=0; i < 10; i++)
     112      783360 :         sum -= gain_block[9-i] * ractx->gain_lpc[i];
     113             : 
     114             :     /* block 47 of G.728 spec */
     115       78336 :     sum = av_clipf(sum, 0, 60);
     116             : 
     117             :     /* block 48 of G.728 spec */
     118             :     /* exp(sum * 0.1151292546497) == pow(10.0,sum/20) */
     119       78336 :     sumsum = exp(sum * 0.1151292546497) * gain * (1.0/(1<<23));
     120             : 
     121      470016 :     for (i=0; i < 5; i++)
     122      391680 :         buffer[i] = codetable[cb_coef][i] * sumsum;
     123             : 
     124       78336 :     sum = avpriv_scalarproduct_float_c(buffer, buffer, 5);
     125             : 
     126       78336 :     sum = FFMAX(sum, 5.0 / (1<<24));
     127             : 
     128             :     /* shift and store */
     129       78336 :     memmove(gain_block, gain_block + 1, 9 * sizeof(*gain_block));
     130             : 
     131       78336 :     gain_block[9] = 10 * log10(sum) + (10*log10(((1<<24)/5.)) - 32);
     132             : 
     133       78336 :     ff_celp_lp_synthesis_filterf(block, ractx->sp_lpc, buffer, 5, 36);
     134       78336 : }
     135             : 
     136             : /**
     137             :  * Hybrid window filtering, see blocks 36 and 49 of the G.728 specification.
     138             :  *
     139             :  * @param order   filter order
     140             :  * @param n       input length
     141             :  * @param non_rec number of non-recursive samples
     142             :  * @param out     filter output
     143             :  * @param hist    pointer to the input history of the filter
     144             :  * @param out     pointer to the non-recursive part of the output
     145             :  * @param out2    pointer to the recursive part of the output
     146             :  * @param window  pointer to the windowing function table
     147             :  */
     148       19584 : static void do_hybrid_window(RA288Context *ractx,
     149             :                              int order, int n, int non_rec, float *out,
     150             :                              float *hist, float *out2, const float *window)
     151             : {
     152             :     int i;
     153             :     float buffer1[MAX_BACKWARD_FILTER_ORDER + 1];
     154             :     float buffer2[MAX_BACKWARD_FILTER_ORDER + 1];
     155       19584 :     LOCAL_ALIGNED(32, float, work, [FFALIGN(MAX_BACKWARD_FILTER_ORDER +
     156             :                                             MAX_BACKWARD_FILTER_LEN   +
     157             :                                             MAX_BACKWARD_FILTER_NONREC, 16)]);
     158             : 
     159             :     av_assert2(order>=0);
     160             : 
     161       19584 :     ractx->fdsp->vector_fmul(work, window, hist, FFALIGN(order + n + non_rec, 16));
     162             : 
     163       19584 :     convolve(buffer1, work + order    , n      , order);
     164       19584 :     convolve(buffer2, work + order + n, non_rec, order);
     165             : 
     166      489600 :     for (i=0; i <= order; i++) {
     167      470016 :         out2[i] = out2[i] * 0.5625 + buffer1[i];
     168      470016 :         out [i] = out2[i]          + buffer2[i];
     169             :     }
     170             : 
     171             :     /* Multiply by the white noise correcting factor (WNCF). */
     172       19584 :     *out *= 257.0 / 256.0;
     173       19584 : }
     174             : 
     175             : /**
     176             :  * Backward synthesis filter, find the LPC coefficients from past speech data.
     177             :  */
     178       19584 : static void backward_filter(RA288Context *ractx,
     179             :                             float *hist, float *rec, const float *window,
     180             :                             float *lpc, const float *tab,
     181             :                             int order, int n, int non_rec, int move_size)
     182             : {
     183             :     float temp[MAX_BACKWARD_FILTER_ORDER+1];
     184             : 
     185       19584 :     do_hybrid_window(ractx, order, n, non_rec, temp, hist, rec, window);
     186             : 
     187       19584 :     if (!compute_lpc_coefs(temp, order, lpc, 0, 1, 1))
     188       19582 :         ractx->fdsp->vector_fmul(lpc, lpc, tab, FFALIGN(order, 16));
     189             : 
     190       19584 :     memmove(hist, hist + n, move_size*sizeof(*hist));
     191       19584 : }
     192             : 
     193        2448 : static int ra288_decode_frame(AVCodecContext * avctx, void *data,
     194             :                               int *got_frame_ptr, AVPacket *avpkt)
     195             : {
     196        2448 :     AVFrame *frame     = data;
     197        2448 :     const uint8_t *buf = avpkt->data;
     198        2448 :     int buf_size = avpkt->size;
     199             :     float *out;
     200             :     int i, ret;
     201        2448 :     RA288Context *ractx = avctx->priv_data;
     202             :     GetBitContext gb;
     203             : 
     204        2448 :     if (buf_size < avctx->block_align) {
     205           0 :         av_log(avctx, AV_LOG_ERROR,
     206             :                "Error! Input buffer is too small [%d<%d]\n",
     207             :                buf_size, avctx->block_align);
     208           0 :         return AVERROR_INVALIDDATA;
     209             :     }
     210             : 
     211        2448 :     ret = init_get_bits8(&gb, buf, avctx->block_align);
     212        2448 :     if (ret < 0)
     213           0 :         return ret;
     214             : 
     215             :     /* get output buffer */
     216        2448 :     frame->nb_samples = RA288_BLOCK_SIZE * RA288_BLOCKS_PER_FRAME;
     217        2448 :     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
     218           0 :         return ret;
     219        2448 :     out = (float *)frame->data[0];
     220             : 
     221       80784 :     for (i=0; i < RA288_BLOCKS_PER_FRAME; i++) {
     222       78336 :         float gain = amptable[get_bits(&gb, 3)];
     223       78336 :         int cb_coef = get_bits(&gb, 6 + (i&1));
     224             : 
     225       78336 :         decode(ractx, gain, cb_coef);
     226             : 
     227       78336 :         memcpy(out, &ractx->sp_hist[70 + 36], RA288_BLOCK_SIZE * sizeof(*out));
     228       78336 :         out += RA288_BLOCK_SIZE;
     229             : 
     230       78336 :         if ((i & 7) == 3) {
     231        9792 :             backward_filter(ractx, ractx->sp_hist, ractx->sp_rec, syn_window,
     232        9792 :                             ractx->sp_lpc, syn_bw_tab, 36, 40, 35, 70);
     233             : 
     234        9792 :             backward_filter(ractx, ractx->gain_hist, ractx->gain_rec, gain_window,
     235        9792 :                             ractx->gain_lpc, gain_bw_tab, 10, 8, 20, 28);
     236             :         }
     237             :     }
     238             : 
     239        2448 :     *got_frame_ptr = 1;
     240             : 
     241        2448 :     return avctx->block_align;
     242             : }
     243             : 
     244             : AVCodec ff_ra_288_decoder = {
     245             :     .name           = "real_288",
     246             :     .long_name      = NULL_IF_CONFIG_SMALL("RealAudio 2.0 (28.8K)"),
     247             :     .type           = AVMEDIA_TYPE_AUDIO,
     248             :     .id             = AV_CODEC_ID_RA_288,
     249             :     .priv_data_size = sizeof(RA288Context),
     250             :     .init           = ra288_decode_init,
     251             :     .decode         = ra288_decode_frame,
     252             :     .close          = ra288_decode_close,
     253             :     .capabilities   = AV_CODEC_CAP_DR1,
     254             : };

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