2 * Interface to libgsm for gsm encoding/decoding
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/decoding
28 // The idiosyncrasies of GSM-in-WAV are explained at http://kbs.cs.tu-berlin.de/~jutta/toast.html
37 #include "libavutil/channel_layout.h"
38 #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 },
145 typedef struct LibGSMDecodeContext {
146 struct gsm_state *state;
147 } LibGSMDecodeContext;
149 static av_cold int libgsm_decode_init(AVCodecContext *avctx) {
150 LibGSMDecodeContext *s = avctx->priv_data;
153 avctx->channel_layout = AV_CH_LAYOUT_MONO;
154 if (!avctx->sample_rate)
155 avctx->sample_rate = 8000;
156 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
158 s->state = gsm_create();
160 switch(avctx->codec_id) {
161 case AV_CODEC_ID_GSM:
162 avctx->frame_size = GSM_FRAME_SIZE;
163 avctx->block_align = GSM_BLOCK_SIZE;
165 case AV_CODEC_ID_GSM_MS: {
167 gsm_option(s->state, GSM_OPT_WAV49, &one);
168 avctx->frame_size = 2 * GSM_FRAME_SIZE;
169 avctx->block_align = GSM_MS_BLOCK_SIZE;
176 static av_cold int libgsm_decode_close(AVCodecContext *avctx) {
177 LibGSMDecodeContext *s = avctx->priv_data;
179 gsm_destroy(s->state);
184 static int libgsm_decode_frame(AVCodecContext *avctx, void *data,
185 int *got_frame_ptr, AVPacket *avpkt)
188 LibGSMDecodeContext *s = avctx->priv_data;
189 AVFrame *frame = data;
190 uint8_t *buf = avpkt->data;
191 int buf_size = avpkt->size;
194 if (buf_size < avctx->block_align) {
195 av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
196 return AVERROR_INVALIDDATA;
199 /* get output buffer */
200 frame->nb_samples = avctx->frame_size;
201 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
203 samples = (int16_t *)frame->data[0];
205 for (i = 0; i < avctx->frame_size / GSM_FRAME_SIZE; i++) {
206 if ((ret = gsm_decode(s->state, buf, samples)) < 0)
208 buf += GSM_BLOCK_SIZE;
209 samples += GSM_FRAME_SIZE;
214 return avctx->block_align;
217 static void libgsm_flush(AVCodecContext *avctx) {
218 LibGSMDecodeContext *s = avctx->priv_data;
221 gsm_destroy(s->state);
222 s->state = gsm_create();
223 if (avctx->codec_id == AV_CODEC_ID_GSM_MS)
224 gsm_option(s->state, GSM_OPT_WAV49, &one);
227 #if CONFIG_LIBGSM_DECODER
228 AVCodec ff_libgsm_decoder = {
230 .long_name = NULL_IF_CONFIG_SMALL("libgsm GSM"),
231 .type = AVMEDIA_TYPE_AUDIO,
232 .id = AV_CODEC_ID_GSM,
233 .priv_data_size = sizeof(LibGSMDecodeContext),
234 .init = libgsm_decode_init,
235 .close = libgsm_decode_close,
236 .decode = libgsm_decode_frame,
237 .flush = libgsm_flush,
238 .capabilities = CODEC_CAP_DR1,
241 #if CONFIG_LIBGSM_MS_DECODER
242 AVCodec ff_libgsm_ms_decoder = {
244 .long_name = NULL_IF_CONFIG_SMALL("libgsm GSM Microsoft variant"),
245 .type = AVMEDIA_TYPE_AUDIO,
246 .id = AV_CODEC_ID_GSM_MS,
247 .priv_data_size = sizeof(LibGSMDecodeContext),
248 .init = libgsm_decode_init,
249 .close = libgsm_decode_close,
250 .decode = libgsm_decode_frame,
251 .flush = libgsm_flush,
252 .capabilities = CODEC_CAP_DR1,