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libgsmdec.c
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1 /*
2  * Interface to libgsm for GSM decoding
3  * Copyright (c) 2005 Alban Bedel <albeu@free.fr>
4  * Copyright (c) 2006, 2007 Michel Bardiaux <mbardiaux@mediaxim.be>
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  * Interface to libgsm for GSM decoding
26  */
27 
28 // The idiosyncrasies of GSM-in-WAV are explained at http://kbs.cs.tu-berlin.de/~jutta/toast.html
29 
30 #include "config.h"
31 #if HAVE_GSM_H
32 #include <gsm.h>
33 #else
34 #include <gsm/gsm.h>
35 #endif
36 
38 #include "libavutil/common.h"
39 
40 #include "avcodec.h"
41 #include "internal.h"
42 #include "gsm.h"
43 
44 typedef struct LibGSMDecodeContext {
45  struct gsm_state *state;
47 
50 
51  avctx->channels = 1;
53  if (!avctx->sample_rate)
54  avctx->sample_rate = 8000;
56 
57  s->state = gsm_create();
58 
59  switch(avctx->codec_id) {
60  case AV_CODEC_ID_GSM:
61  avctx->frame_size = GSM_FRAME_SIZE;
62  avctx->block_align = GSM_BLOCK_SIZE;
63  break;
64  case AV_CODEC_ID_GSM_MS: {
65  int one = 1;
66  gsm_option(s->state, GSM_OPT_WAV49, &one);
67  avctx->frame_size = 2 * GSM_FRAME_SIZE;
69  }
70  }
71 
72  return 0;
73 }
74 
77 
78  gsm_destroy(s->state);
79  s->state = NULL;
80  return 0;
81 }
82 
83 static int libgsm_decode_frame(AVCodecContext *avctx, void *data,
84  int *got_frame_ptr, AVPacket *avpkt)
85 {
86  int i, ret;
88  AVFrame *frame = data;
89  uint8_t *buf = avpkt->data;
90  int buf_size = avpkt->size;
91  int16_t *samples;
92 
93  if (buf_size < avctx->block_align) {
94  av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
95  return AVERROR_INVALIDDATA;
96  }
97 
98  /* get output buffer */
99  frame->nb_samples = avctx->frame_size;
100  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
101  return ret;
102  samples = (int16_t *)frame->data[0];
103 
104  for (i = 0; i < avctx->frame_size / GSM_FRAME_SIZE; i++) {
105  if ((ret = gsm_decode(s->state, buf, samples)) < 0)
106  return -1;
107  buf += GSM_BLOCK_SIZE;
108  samples += GSM_FRAME_SIZE;
109  }
110 
111  *got_frame_ptr = 1;
112 
113  return avctx->block_align;
114 }
115 
116 static void libgsm_flush(AVCodecContext *avctx) {
117  LibGSMDecodeContext *s = avctx->priv_data;
118  int one = 1;
119 
120  gsm_destroy(s->state);
121  s->state = gsm_create();
122  if (avctx->codec_id == AV_CODEC_ID_GSM_MS)
123  gsm_option(s->state, GSM_OPT_WAV49, &one);
124 }
125 
126 #if CONFIG_LIBGSM_DECODER
127 AVCodec ff_libgsm_decoder = {
128  .name = "libgsm",
129  .long_name = NULL_IF_CONFIG_SMALL("libgsm GSM"),
130  .type = AVMEDIA_TYPE_AUDIO,
131  .id = AV_CODEC_ID_GSM,
132  .priv_data_size = sizeof(LibGSMDecodeContext),
134  .close = libgsm_decode_close,
136  .flush = libgsm_flush,
137  .capabilities = AV_CODEC_CAP_DR1,
138  .wrapper_name = "libgsm",
139 };
140 #endif
141 #if CONFIG_LIBGSM_MS_DECODER
142 AVCodec ff_libgsm_ms_decoder = {
143  .name = "libgsm_ms",
144  .long_name = NULL_IF_CONFIG_SMALL("libgsm GSM Microsoft variant"),
145  .type = AVMEDIA_TYPE_AUDIO,
146  .id = AV_CODEC_ID_GSM_MS,
147  .priv_data_size = sizeof(LibGSMDecodeContext),
149  .close = libgsm_decode_close,
151  .flush = libgsm_flush,
152  .capabilities = AV_CODEC_CAP_DR1,
153  .wrapper_name = "libgsm",
154 };
155 #endif
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:768
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
#define GSM_FRAME_SIZE
Definition: gsm.h:30
This structure describes decoded (raw) audio or video data.
Definition: frame.h:201
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
static void flush(AVCodecContext *avctx)
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
int size
Definition: avcodec.h:1415
static int libgsm_decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
Definition: libgsmdec.c:83
AVCodec.
Definition: avcodec.h:3365
int block_align
number of bytes per packet if constant and known or 0 Used by some WAV based audio codecs...
Definition: avcodec.h:2194
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:42
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:2165
uint8_t
#define av_cold
Definition: attributes.h:82
#define GSM_MS_BLOCK_SIZE
Definition: gsm.h:26
static AVFrame * frame
#define GSM_BLOCK_SIZE
Definition: gsm.h:25
uint8_t * data
Definition: avcodec.h:1414
static av_cold int libgsm_decode_init(AVCodecContext *avctx)
Definition: libgsmdec.c:48
#define av_log(a,...)
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
const char * name
Name of the codec implementation.
Definition: avcodec.h:3372
static void libgsm_flush(AVCodecContext *avctx)
Definition: libgsmdec.c:116
uint64_t channel_layout
Audio channel layout.
Definition: avcodec.h:2208
audio channel layout utility functions
struct gsm_state * state
Definition: libgsmdec.c:45
int frame_size
Number of samples per channel in an audio frame.
Definition: avcodec.h:2177
Libavcodec external API header.
enum AVCodecID codec_id
Definition: avcodec.h:1512
int sample_rate
samples per second
Definition: avcodec.h:2157
main external API structure.
Definition: avcodec.h:1502
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1886
void * buf
Definition: avisynth_c.h:690
static av_cold int libgsm_decode_close(AVCodecContext *avctx)
Definition: libgsmdec.c:75
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:215
common internal api header.
common internal and external API header
signed 16 bits
Definition: samplefmt.h:61
void * priv_data
Definition: avcodec.h:1529
as in Berlin toast format
Definition: avcodec.h:569
int channels
number of audio channels
Definition: avcodec.h:2158
#define AV_CH_LAYOUT_MONO
This structure stores compressed data.
Definition: avcodec.h:1391
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:267
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:956
for(j=16;j >0;--j)