LCOV - code coverage report
Current view: top level - libavcodec - adxdec.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 51 81 63.0 %
Date: 2017-12-17 11:58:42 Functions: 3 4 75.0 %

          Line data    Source code
       1             : /*
       2             :  * ADX ADPCM codecs
       3             :  * Copyright (c) 2001,2003 BERO
       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/intreadwrite.h"
      23             : #include "avcodec.h"
      24             : #include "adx.h"
      25             : #include "get_bits.h"
      26             : #include "internal.h"
      27             : 
      28             : /**
      29             :  * @file
      30             :  * SEGA CRI adx codecs.
      31             :  *
      32             :  * Reference documents:
      33             :  * http://ku-www.ss.titech.ac.jp/~yatsushi/adx.html
      34             :  * adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/
      35             :  */
      36             : 
      37           4 : static av_cold int adx_decode_init(AVCodecContext *avctx)
      38             : {
      39           4 :     ADXContext *c = avctx->priv_data;
      40             :     int ret, header_size;
      41             : 
      42           4 :     if (avctx->extradata_size >= 24) {
      43           4 :         if ((ret = ff_adx_decode_header(avctx, avctx->extradata,
      44             :                                         avctx->extradata_size, &header_size,
      45           4 :                                         c->coeff)) < 0) {
      46           0 :             av_log(avctx, AV_LOG_ERROR, "error parsing ADX header\n");
      47           0 :             return AVERROR_INVALIDDATA;
      48             :         }
      49           4 :         c->channels      = avctx->channels;
      50           4 :         c->header_parsed = 1;
      51             :     }
      52             : 
      53           4 :     avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
      54             : 
      55           4 :     return 0;
      56             : }
      57             : 
      58             : /**
      59             :  * Decode 32 samples from 18 bytes.
      60             :  *
      61             :  * A 16-bit scalar value is applied to 32 residuals, which then have a
      62             :  * 2nd-order LPC filter applied to it to form the output signal for a single
      63             :  * channel.
      64             :  */
      65       33076 : static int adx_decode(ADXContext *c, int16_t *out, int offset,
      66             :                       const uint8_t *in, int ch)
      67             : {
      68       33076 :     ADXChannelState *prev = &c->prev[ch];
      69             :     GetBitContext gb;
      70       33076 :     int scale = AV_RB16(in);
      71             :     int i;
      72             :     int s0, s1, s2, d;
      73             : 
      74             :     /* check if this is an EOF packet */
      75       33076 :     if (scale & 0x8000)
      76           0 :         return -1;
      77             : 
      78       33076 :     init_get_bits(&gb, in + 2, (BLOCK_SIZE - 2) * 8);
      79       33076 :     out += offset;
      80       33076 :     s1 = prev->s1;
      81       33076 :     s2 = prev->s2;
      82     1091508 :     for (i = 0; i < BLOCK_SAMPLES; i++) {
      83     1058432 :         d  = get_sbits(&gb, 4);
      84     1058432 :         s0 = ((d * (1 << COEFF_BITS)) * scale + c->coeff[0] * s1 + c->coeff[1] * s2) >> COEFF_BITS;
      85     1058432 :         s2 = s1;
      86     1058432 :         s1 = av_clip_int16(s0);
      87     1058432 :         *out++ = s1;
      88             :     }
      89       33076 :     prev->s1 = s1;
      90       33076 :     prev->s2 = s2;
      91             : 
      92       33076 :     return 0;
      93             : }
      94             : 
      95       16538 : static int adx_decode_frame(AVCodecContext *avctx, void *data,
      96             :                             int *got_frame_ptr, AVPacket *avpkt)
      97             : {
      98       16538 :     AVFrame *frame      = data;
      99       16538 :     int buf_size        = avpkt->size;
     100       16538 :     ADXContext *c       = avctx->priv_data;
     101             :     int16_t **samples;
     102             :     int samples_offset;
     103       16538 :     const uint8_t *buf  = avpkt->data;
     104       16538 :     const uint8_t *buf_end = buf + avpkt->size;
     105             :     int num_blocks, ch, ret;
     106             : 
     107       16538 :     if (c->eof) {
     108           0 :         *got_frame_ptr = 0;
     109           0 :         return buf_size;
     110             :     }
     111             : 
     112       16538 :     if (!c->header_parsed && buf_size >= 2 && AV_RB16(buf) == 0x8000) {
     113             :         int header_size;
     114           0 :         if ((ret = ff_adx_decode_header(avctx, buf, buf_size, &header_size,
     115           0 :                                         c->coeff)) < 0) {
     116           0 :             av_log(avctx, AV_LOG_ERROR, "error parsing ADX header\n");
     117           0 :             return AVERROR_INVALIDDATA;
     118             :         }
     119           0 :         c->channels      = avctx->channels;
     120           0 :         c->header_parsed = 1;
     121           0 :         if (buf_size < header_size)
     122           0 :             return AVERROR_INVALIDDATA;
     123           0 :         buf      += header_size;
     124           0 :         buf_size -= header_size;
     125             :     }
     126       16538 :     if (!c->header_parsed)
     127           0 :         return AVERROR_INVALIDDATA;
     128             : 
     129             :     /* calculate number of blocks in the packet */
     130       16538 :     num_blocks = buf_size / (BLOCK_SIZE * c->channels);
     131             : 
     132             :     /* if the packet is not an even multiple of BLOCK_SIZE, check for an EOF
     133             :        packet */
     134       16538 :     if (!num_blocks || buf_size % (BLOCK_SIZE * avctx->channels)) {
     135           0 :         if (buf_size >= 4 && (AV_RB16(buf) & 0x8000)) {
     136           0 :             c->eof = 1;
     137           0 :             *got_frame_ptr = 0;
     138           0 :             return avpkt->size;
     139             :         }
     140           0 :         return AVERROR_INVALIDDATA;
     141             :     }
     142             : 
     143             :     /* get output buffer */
     144       16538 :     frame->nb_samples = num_blocks * BLOCK_SAMPLES;
     145       16538 :     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
     146           0 :         return ret;
     147       16538 :     samples = (int16_t **)frame->extended_data;
     148       16538 :     samples_offset = 0;
     149             : 
     150       49614 :     while (num_blocks--) {
     151       49614 :         for (ch = 0; ch < c->channels; ch++) {
     152       33076 :             if (buf_end - buf < BLOCK_SIZE || adx_decode(c, samples[ch], samples_offset, buf, ch)) {
     153           0 :                 c->eof = 1;
     154           0 :                 buf = avpkt->data + avpkt->size;
     155           0 :                 break;
     156             :             }
     157       33076 :             buf_size -= BLOCK_SIZE;
     158       33076 :             buf      += BLOCK_SIZE;
     159             :         }
     160       16538 :         if (!c->eof)
     161       16538 :             samples_offset += BLOCK_SAMPLES;
     162             :     }
     163             : 
     164       16538 :     frame->nb_samples = samples_offset;
     165       16538 :     *got_frame_ptr = 1;
     166             : 
     167       16538 :     return buf - avpkt->data;
     168             : }
     169             : 
     170           0 : static void adx_decode_flush(AVCodecContext *avctx)
     171             : {
     172           0 :     ADXContext *c = avctx->priv_data;
     173           0 :     memset(c->prev, 0, sizeof(c->prev));
     174           0 :     c->eof = 0;
     175           0 : }
     176             : 
     177             : AVCodec ff_adpcm_adx_decoder = {
     178             :     .name           = "adpcm_adx",
     179             :     .long_name      = NULL_IF_CONFIG_SMALL("SEGA CRI ADX ADPCM"),
     180             :     .type           = AVMEDIA_TYPE_AUDIO,
     181             :     .id             = AV_CODEC_ID_ADPCM_ADX,
     182             :     .priv_data_size = sizeof(ADXContext),
     183             :     .init           = adx_decode_init,
     184             :     .decode         = adx_decode_frame,
     185             :     .flush          = adx_decode_flush,
     186             :     .capabilities   = AV_CODEC_CAP_DR1,
     187             :     .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P,
     188             :                                                       AV_SAMPLE_FMT_NONE },
     189             : };

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