Libav
libgsmenc.c
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1 /*
2  * Interface to libgsm for GSM encoding
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 Libav.
7  *
8  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
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 
37 #include "libavutil/common.h"
38 
39 #include "avcodec.h"
40 #include "internal.h"
41 #include "gsm.h"
42 
44  if (avctx->channels > 1) {
45  av_log(avctx, AV_LOG_ERROR, "Mono required for GSM, got %d channels\n",
46  avctx->channels);
47  return -1;
48  }
49 
50  if (avctx->sample_rate != 8000) {
51  av_log(avctx, AV_LOG_ERROR, "Sample rate 8000Hz required for GSM, got %dHz\n",
52  avctx->sample_rate);
54  return -1;
55  }
56  if (avctx->bit_rate != 13000 /* Official */ &&
57  avctx->bit_rate != 13200 /* Very common */ &&
58  avctx->bit_rate != 0 /* Unknown; a.o. mov does not set bitrate when decoding */ ) {
59  av_log(avctx, AV_LOG_ERROR, "Bitrate 13000bps required for GSM, got %dbps\n",
60  avctx->bit_rate);
62  return -1;
63  }
64 
65  avctx->priv_data = gsm_create();
66 
67  switch(avctx->codec_id) {
68  case AV_CODEC_ID_GSM:
69  avctx->frame_size = GSM_FRAME_SIZE;
70  avctx->block_align = GSM_BLOCK_SIZE;
71  break;
72  case AV_CODEC_ID_GSM_MS: {
73  int one = 1;
74  gsm_option(avctx->priv_data, GSM_OPT_WAV49, &one);
75  avctx->frame_size = 2*GSM_FRAME_SIZE;
77  }
78  }
79 
80  return 0;
81 }
82 
84  gsm_destroy(avctx->priv_data);
85  avctx->priv_data = NULL;
86  return 0;
87 }
88 
89 static int libgsm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
90  const AVFrame *frame, int *got_packet_ptr)
91 {
92  int ret;
93  gsm_signal *samples = (gsm_signal *)frame->data[0];
94  struct gsm_state *state = avctx->priv_data;
95 
96  if ((ret = ff_alloc_packet(avpkt, avctx->block_align))) {
97  av_log(avctx, AV_LOG_ERROR, "Error getting output packet\n");
98  return ret;
99  }
100 
101  switch(avctx->codec_id) {
102  case AV_CODEC_ID_GSM:
103  gsm_encode(state, samples, avpkt->data);
104  break;
105  case AV_CODEC_ID_GSM_MS:
106  gsm_encode(state, samples, avpkt->data);
107  gsm_encode(state, samples + GSM_FRAME_SIZE, avpkt->data + 32);
108  }
109 
110  *got_packet_ptr = 1;
111  return 0;
112 }
113 
114 
116  .name = "libgsm",
117  .long_name = NULL_IF_CONFIG_SMALL("libgsm GSM"),
118  .type = AVMEDIA_TYPE_AUDIO,
119  .id = AV_CODEC_ID_GSM,
120  .init = libgsm_encode_init,
121  .encode2 = libgsm_encode_frame,
122  .close = libgsm_encode_close,
123  .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
125 };
126 
128  .name = "libgsm_ms",
129  .long_name = NULL_IF_CONFIG_SMALL("libgsm GSM Microsoft variant"),
130  .type = AVMEDIA_TYPE_AUDIO,
131  .id = AV_CODEC_ID_GSM_MS,
132  .init = libgsm_encode_init,
133  .encode2 = libgsm_encode_frame,
134  .close = libgsm_encode_close,
135  .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
137 };
#define GSM_FRAME_SIZE
Definition: gsm.h:30
This structure describes decoded (raw) audio or video data.
Definition: frame.h:135
AVCodec ff_libgsm_encoder
Definition: libgsmenc.c:115
AVCodec.
Definition: avcodec.h:2790
int block_align
number of bytes per packet if constant and known or 0 Used by some WAV based audio codecs...
Definition: avcodec.h:1822
#define av_cold
Definition: attributes.h:66
#define GSM_MS_BLOCK_SIZE
Definition: gsm.h:26
#define GSM_BLOCK_SIZE
Definition: gsm.h:25
uint8_t * data
Definition: avcodec.h:967
static av_cold int libgsm_encode_init(AVCodecContext *avctx)
Definition: libgsmenc.c:43
#define FF_COMPLIANCE_UNOFFICIAL
Allow unofficial extensions.
Definition: avcodec.h:2339
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:123
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:150
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:168
const char * name
Name of the codec implementation.
Definition: avcodec.h:2797
int bit_rate
the average bitrate
Definition: avcodec.h:1108
int ff_alloc_packet(AVPacket *avpkt, int size)
Check AVPacket size and/or allocate data.
Definition: utils.c:1236
AVCodec ff_libgsm_ms_encoder
Definition: libgsmenc.c:127
if(ac->has_optimized_func)
int frame_size
Number of samples per channel in an audio frame.
Definition: avcodec.h:1805
NULL
Definition: eval.c:55
Libavcodec external API header.
AVSampleFormat
Audio Sample Formats.
Definition: samplefmt.h:61
enum AVCodecID codec_id
Definition: avcodec.h:1061
AV_SAMPLE_FMT_NONE
Definition: avconv_filter.c:68
int sample_rate
samples per second
Definition: avcodec.h:1785
main external API structure.
Definition: avcodec.h:1044
static uint32_t state
Definition: trasher.c:27
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:141
static int libgsm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame, int *got_packet_ptr)
Definition: libgsmenc.c:89
common internal api header.
common internal and external API header
signed 16 bits
Definition: samplefmt.h:64
void * priv_data
Definition: avcodec.h:1086
as in Berlin toast format
Definition: avcodec.h:396
int channels
number of audio channels
Definition: avcodec.h:1786
This structure stores compressed data.
Definition: avcodec.h:944
int strict_std_compliance
strictly follow the standard (MPEG4, ...).
Definition: avcodec.h:2335
static av_cold int libgsm_encode_close(AVCodecContext *avctx)
Definition: libgsmenc.c:83