LCOV - code coverage report
Current view: top level - libavcodec - g722dec.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 39 40 97.5 %
Date: 2017-12-11 04:34:20 Functions: 2 2 100.0 %

          Line data    Source code
       1             : /*
       2             :  * Copyright (c) CMU 1993 Computer Science, Speech Group
       3             :  *                        Chengxiang Lu and Alex Hauptmann
       4             :  * Copyright (c) 2005 Steve Underwood <steveu at coppice.org>
       5             :  * Copyright (c) 2009 Kenan Gillet
       6             :  * Copyright (c) 2010 Martin Storsjo
       7             :  *
       8             :  * This file is part of FFmpeg.
       9             :  *
      10             :  * FFmpeg is free software; you can redistribute it and/or
      11             :  * modify it under the terms of the GNU Lesser General Public
      12             :  * License as published by the Free Software Foundation; either
      13             :  * version 2.1 of the License, or (at your option) any later version.
      14             :  *
      15             :  * FFmpeg is distributed in the hope that it will be useful,
      16             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      17             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      18             :  * Lesser General Public License for more details.
      19             :  *
      20             :  * You should have received a copy of the GNU Lesser General Public
      21             :  * License along with FFmpeg; if not, write to the Free Software
      22             :  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
      23             :  */
      24             : 
      25             : /**
      26             :  * @file
      27             :  * G.722 ADPCM audio decoder
      28             :  *
      29             :  * This G.722 decoder is a bit-exact implementation of the ITU G.722
      30             :  * specification for all three specified bitrates - 64000bps, 56000bps
      31             :  * and 48000bps. It passes the ITU tests.
      32             :  *
      33             :  * @note For the 56000bps and 48000bps bitrates, the lowest 1 or 2 bits
      34             :  *       respectively of each byte are ignored.
      35             :  */
      36             : 
      37             : #include "libavutil/channel_layout.h"
      38             : #include "libavutil/opt.h"
      39             : #include "avcodec.h"
      40             : #include "get_bits.h"
      41             : #include "g722.h"
      42             : #include "internal.h"
      43             : 
      44             : #define OFFSET(x) offsetof(G722Context, x)
      45             : #define AD AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_DECODING_PARAM
      46             : static const AVOption options[] = {
      47             :     { "bits_per_codeword", "Bits per G722 codeword", OFFSET(bits_per_codeword), AV_OPT_TYPE_INT, { .i64 = 8 }, 6, 8, AD },
      48             :     { NULL }
      49             : };
      50             : 
      51             : static const AVClass g722_decoder_class = {
      52             :     .class_name = "g722 decoder",
      53             :     .item_name  = av_default_item_name,
      54             :     .option     = options,
      55             :     .version    = LIBAVUTIL_VERSION_INT,
      56             : };
      57             : 
      58           4 : static av_cold int g722_decode_init(AVCodecContext * avctx)
      59             : {
      60           4 :     G722Context *c = avctx->priv_data;
      61             : 
      62           4 :     avctx->channels       = 1;
      63           4 :     avctx->channel_layout = AV_CH_LAYOUT_MONO;
      64           4 :     avctx->sample_fmt     = AV_SAMPLE_FMT_S16;
      65             : 
      66           4 :     c->band[0].scale_factor = 8;
      67           4 :     c->band[1].scale_factor = 2;
      68           4 :     c->prev_samples_pos = 22;
      69             : 
      70           4 :     ff_g722dsp_init(&c->dsp);
      71             : 
      72           4 :     return 0;
      73             : }
      74             : 
      75             : static const int16_t low_inv_quant5[32] = {
      76             :      -35,   -35, -2919, -2195, -1765, -1458, -1219, -1023,
      77             :     -858,  -714,  -587,  -473,  -370,  -276,  -190,  -110,
      78             :     2919,  2195,  1765,  1458,  1219,  1023,   858,   714,
      79             :      587,   473,   370,   276,   190,   110,    35,   -35
      80             : };
      81             : 
      82             : static const int16_t * const low_inv_quants[3] = { ff_g722_low_inv_quant6,
      83             :                                                            low_inv_quant5,
      84             :                                                    ff_g722_low_inv_quant4 };
      85             : 
      86         179 : static int g722_decode_frame(AVCodecContext *avctx, void *data,
      87             :                              int *got_frame_ptr, AVPacket *avpkt)
      88             : {
      89         179 :     G722Context *c = avctx->priv_data;
      90         179 :     AVFrame *frame = data;
      91             :     int16_t *out_buf;
      92             :     int j, ret;
      93         179 :     const int skip = 8 - c->bits_per_codeword;
      94         179 :     const int16_t *quantizer_table = low_inv_quants[skip];
      95             :     GetBitContext gb;
      96             : 
      97             :     /* get output buffer */
      98         179 :     frame->nb_samples = avpkt->size * 2;
      99         179 :     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
     100           0 :         return ret;
     101         179 :     out_buf = (int16_t *)frame->data[0];
     102             : 
     103         179 :     init_get_bits(&gb, avpkt->data, avpkt->size * 8);
     104             : 
     105      218505 :     for (j = 0; j < avpkt->size; j++) {
     106             :         int ilow, ihigh, rlow, rhigh, dhigh;
     107             :         int xout[2];
     108             : 
     109      218326 :         ihigh = get_bits(&gb, 2);
     110      218326 :         ilow = get_bits(&gb, 6 - skip);
     111      218326 :         skip_bits(&gb, skip);
     112             : 
     113      436652 :         rlow = av_clip_intp2((c->band[0].scale_factor * quantizer_table[ilow] >> 10)
     114      218326 :                       + c->band[0].s_predictor, 14);
     115             : 
     116      218326 :         ff_g722_update_low_predictor(&c->band[0], ilow >> (2 - skip));
     117             : 
     118      218326 :         dhigh = c->band[1].scale_factor * ff_g722_high_inv_quant[ihigh] >> 10;
     119      218326 :         rhigh = av_clip_intp2(dhigh + c->band[1].s_predictor, 14);
     120             : 
     121      218326 :         ff_g722_update_high_predictor(&c->band[1], dhigh, ihigh);
     122             : 
     123      218326 :         c->prev_samples[c->prev_samples_pos++] = rlow + rhigh;
     124      218326 :         c->prev_samples[c->prev_samples_pos++] = rlow - rhigh;
     125      218326 :         c->dsp.apply_qmf(c->prev_samples + c->prev_samples_pos - 24, xout);
     126      218326 :         *out_buf++ = av_clip_int16(xout[0] >> 11);
     127      218326 :         *out_buf++ = av_clip_int16(xout[1] >> 11);
     128      218326 :         if (c->prev_samples_pos >= PREV_SAMPLES_BUF_SIZE) {
     129         434 :             memmove(c->prev_samples, c->prev_samples + c->prev_samples_pos - 22,
     130             :                     22 * sizeof(c->prev_samples[0]));
     131         434 :             c->prev_samples_pos = 22;
     132             :         }
     133             :     }
     134             : 
     135         179 :     *got_frame_ptr = 1;
     136             : 
     137         179 :     return avpkt->size;
     138             : }
     139             : 
     140             : AVCodec ff_adpcm_g722_decoder = {
     141             :     .name           = "g722",
     142             :     .long_name      = NULL_IF_CONFIG_SMALL("G.722 ADPCM"),
     143             :     .type           = AVMEDIA_TYPE_AUDIO,
     144             :     .id             = AV_CODEC_ID_ADPCM_G722,
     145             :     .priv_data_size = sizeof(G722Context),
     146             :     .init           = g722_decode_init,
     147             :     .decode         = g722_decode_frame,
     148             :     .capabilities   = AV_CODEC_CAP_DR1,
     149             :     .priv_class     = &g722_decoder_class,
     150             : };

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