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>
6 * This file is part of FFmpeg.
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.
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.
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
25 * Interface to libgsm for GSM encoding
28 // The idiosyncrasies of GSM-in-WAV are explained at http://kbs.cs.tu-berlin.de/~jutta/toast.html
37 #include "libavutil/common.h"
43 static av_cold
int libgsm_encode_close(AVCodecContext
*avctx
) {
44 gsm_destroy(avctx
->priv_data
);
45 avctx
->priv_data
= NULL
;
49 static av_cold
int libgsm_encode_init(AVCodecContext
*avctx
) {
50 if (avctx
->channels
> 1) {
51 av_log(avctx
, AV_LOG_ERROR
, "Mono required for GSM, got %d channels\n",
56 if (avctx
->sample_rate
!= 8000) {
57 av_log(avctx
, AV_LOG_ERROR
, "Sample rate 8000Hz required for GSM, got %dHz\n",
59 if (avctx
->strict_std_compliance
> FF_COMPLIANCE_UNOFFICIAL
)
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 %dbps\n",
67 if (avctx
->strict_std_compliance
> FF_COMPLIANCE_UNOFFICIAL
)
71 avctx
->priv_data
= gsm_create();
72 if (!avctx
->priv_data
)
75 switch(avctx
->codec_id
) {
77 avctx
->frame_size
= GSM_FRAME_SIZE
;
78 avctx
->block_align
= GSM_BLOCK_SIZE
;
80 case AV_CODEC_ID_GSM_MS
: {
82 gsm_option(avctx
->priv_data
, GSM_OPT_WAV49
, &one
);
83 avctx
->frame_size
= 2*GSM_FRAME_SIZE
;
84 avctx
->block_align
= GSM_MS_BLOCK_SIZE
;
90 libgsm_encode_close(avctx
);
94 static int libgsm_encode_frame(AVCodecContext
*avctx
, AVPacket
*avpkt
,
95 const AVFrame
*frame
, int *got_packet_ptr
)
98 gsm_signal
*samples
= (gsm_signal
*)frame
->data
[0];
99 struct gsm_state
*state
= avctx
->priv_data
;
101 if ((ret
= ff_alloc_packet2(avctx
, avpkt
, avctx
->block_align
)) < 0)
104 switch(avctx
->codec_id
) {
105 case AV_CODEC_ID_GSM
:
106 gsm_encode(state
, samples
, avpkt
->data
);
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);
118 #if CONFIG_LIBGSM_ENCODER
119 AVCodec ff_libgsm_encoder
= {
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
,
128 AV_SAMPLE_FMT_NONE
},
131 #if CONFIG_LIBGSM_MS_ENCODER
132 AVCodec ff_libgsm_ms_encoder
= {
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
,
141 AV_SAMPLE_FMT_NONE
},