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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 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 encoding
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 
37 #include "libavutil/common.h"
38 
39 #include "avcodec.h"
40 #include "internal.h"
41 #include "gsm.h"
42 
44  gsm_destroy(avctx->priv_data);
45  avctx->priv_data = NULL;
46  return 0;
47 }
48 
50  if (avctx->channels > 1) {
51  av_log(avctx, AV_LOG_ERROR, "Mono required for GSM, got %d channels\n",
52  avctx->channels);
53  return -1;
54  }
55 
56  if (avctx->sample_rate != 8000) {
57  av_log(avctx, AV_LOG_ERROR, "Sample rate 8000Hz required for GSM, got %dHz\n",
58  avctx->sample_rate);
60  return -1;
61  }
62  if (avctx->bit_rate != 13000 /* Official */ &&
63  avctx->bit_rate != 13200 /* Very common */ &&
64  avctx->bit_rate != 0 /* Unknown; a.o. mov does not set bitrate when decoding */ ) {
65  av_log(avctx, AV_LOG_ERROR, "Bitrate 13000bps required for GSM, got %"PRId64"bps\n",
66  avctx->bit_rate);
68  return -1;
69  }
70 
71  avctx->priv_data = gsm_create();
72  if (!avctx->priv_data)
73  goto error;
74 
75  switch(avctx->codec_id) {
76  case AV_CODEC_ID_GSM:
77  avctx->frame_size = GSM_FRAME_SIZE;
78  avctx->block_align = GSM_BLOCK_SIZE;
79  break;
80  case AV_CODEC_ID_GSM_MS: {
81  int one = 1;
82  gsm_option(avctx->priv_data, GSM_OPT_WAV49, &one);
83  avctx->frame_size = 2*GSM_FRAME_SIZE;
85  }
86  }
87 
88  return 0;
89 error:
90  libgsm_encode_close(avctx);
91  return -1;
92 }
93 
94 static int libgsm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
95  const AVFrame *frame, int *got_packet_ptr)
96 {
97  int ret;
98  gsm_signal *samples = (gsm_signal *)frame->data[0];
99  struct gsm_state *state = avctx->priv_data;
100 
101  if ((ret = ff_alloc_packet2(avctx, avpkt, avctx->block_align, 0)) < 0)
102  return ret;
103 
104  switch(avctx->codec_id) {
105  case AV_CODEC_ID_GSM:
106  gsm_encode(state, samples, avpkt->data);
107  break;
108  case AV_CODEC_ID_GSM_MS:
109  gsm_encode(state, samples, avpkt->data);
110  gsm_encode(state, samples + GSM_FRAME_SIZE, avpkt->data + 32);
111  }
112 
113  *got_packet_ptr = 1;
114  return 0;
115 }
116 
117 
118 #if CONFIG_LIBGSM_ENCODER
119 AVCodec ff_libgsm_encoder = {
120  .name = "libgsm",
121  .long_name = NULL_IF_CONFIG_SMALL("libgsm GSM"),
122  .type = AVMEDIA_TYPE_AUDIO,
123  .id = AV_CODEC_ID_GSM,
124  .init = libgsm_encode_init,
125  .encode2 = libgsm_encode_frame,
126  .close = libgsm_encode_close,
127  .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
129 };
130 #endif
131 #if CONFIG_LIBGSM_MS_ENCODER
132 AVCodec ff_libgsm_ms_encoder = {
133  .name = "libgsm_ms",
134  .long_name = NULL_IF_CONFIG_SMALL("libgsm GSM Microsoft variant"),
135  .type = AVMEDIA_TYPE_AUDIO,
136  .id = AV_CODEC_ID_GSM_MS,
137  .init = libgsm_encode_init,
138  .encode2 = libgsm_encode_frame,
139  .close = libgsm_encode_close,
140  .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
142 };
143 #endif
#define NULL
Definition: coverity.c:32
#define GSM_FRAME_SIZE
Definition: gsm.h:30
This structure describes decoded (raw) audio or video data.
Definition: frame.h:201
int64_t bit_rate
the average bitrate
Definition: avcodec.h:1538
AVCodec.
Definition: avcodec.h:3351
int block_align
number of bytes per packet if constant and known or 0 Used by some WAV based audio codecs...
Definition: avcodec.h:2180
int ff_alloc_packet2(AVCodecContext *avctx, AVPacket *avpkt, int64_t size, int64_t min_size)
Check AVPacket size and/or allocate data.
Definition: encode.c:32
#define av_cold
Definition: attributes.h:82
#define GSM_MS_BLOCK_SIZE
Definition: gsm.h:26
static struct @281 state
static AVFrame * frame
#define GSM_BLOCK_SIZE
Definition: gsm.h:25
uint8_t * data
Definition: avcodec.h:1400
static av_cold int libgsm_encode_init(AVCodecContext *avctx)
Definition: libgsmenc.c:49
#define av_log(a,...)
#define FF_COMPLIANCE_UNOFFICIAL
Allow unofficial extensions.
Definition: avcodec.h:2550
#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:3358
static void error(const char *err)
int frame_size
Number of samples per channel in an audio frame.
Definition: avcodec.h:2163
Libavcodec external API header.
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:58
enum AVCodecID codec_id
Definition: avcodec.h:1498
int sample_rate
samples per second
Definition: avcodec.h:2143
main external API structure.
Definition: avcodec.h:1488
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:215
static int libgsm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame, int *got_packet_ptr)
Definition: libgsmenc.c:94
common internal api header.
common internal and external API header
if(ret< 0)
Definition: vf_mcdeint.c:279
signed 16 bits
Definition: samplefmt.h:61
void * priv_data
Definition: avcodec.h:1515
as in Berlin toast format
Definition: avcodec.h:569
int channels
number of audio channels
Definition: avcodec.h:2144
This structure stores compressed data.
Definition: avcodec.h:1377
int strict_std_compliance
strictly follow the standard (MPEG-4, ...).
Definition: avcodec.h:2546
static av_cold int libgsm_encode_close(AVCodecContext *avctx)
Definition: libgsmenc.c:43