libavcodec/libgsm.c

   1 /*
   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>
   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
  23 /**
  24  * @file
  25  * Interface to libgsm for gsm encoding/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
  37 #include "libavutil/channel_layout.h"
  38 #include "libavutil/common.h"
  39 #include "avcodec.h"
  40 #include "internal.h"
  41 #include "gsm.h"
  42
  43 static av_cold int libgsm_encode_init(AVCodecContext *avctx) {
  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);
  53         if (avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL)
  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);
  61         if (avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL)
  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;
  76         avctx->block_align = GSM_MS_BLOCK_SIZE;
  77         }
  78     }
  79
  80 #if FF_API_OLD_ENCODE_AUDIO
  81     avctx->coded_frame= avcodec_alloc_frame();
  82     if (!avctx->coded_frame) {
  83         gsm_destroy(avctx->priv_data);
  84         return AVERROR(ENOMEM);
  85     }
  86 #endif
  87
  88     return 0;
  89 }
  90
  91 static av_cold int libgsm_encode_close(AVCodecContext *avctx) {
  92 #if FF_API_OLD_ENCODE_AUDIO
  93     av_freep(&avctx->coded_frame);
  94 #endif
  95     gsm_destroy(avctx->priv_data);
  96     avctx->priv_data = NULL;
  97     return 0;
  98 }
  99
 100 static int libgsm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
 101                                const AVFrame *frame, int *got_packet_ptr)
 102 {
 103     int ret;
 104     gsm_signal *samples = (gsm_signal *)frame->data[0];
 105     struct gsm_state *state = avctx->priv_data;
 106
 107     if ((ret = ff_alloc_packet(avpkt, avctx->block_align))) {
 108         av_log(avctx, AV_LOG_ERROR, "Error getting output packet\n");
 109         return ret;
 110     }
 111
 112     switch(avctx->codec_id) {
 113     case AV_CODEC_ID_GSM:
 114         gsm_encode(state, samples, avpkt->data);
 115         break;
 116     case AV_CODEC_ID_GSM_MS:
 117         gsm_encode(state, samples,                  avpkt->data);
 118         gsm_encode(state, samples + GSM_FRAME_SIZE, avpkt->data + 32);
 119     }
 120
 121     *got_packet_ptr = 1;
 122     return 0;
 123 }
 124
 125
 126 AVCodec ff_libgsm_encoder = {
 127     .name           = "libgsm",
 128     .type           = AVMEDIA_TYPE_AUDIO,
 129     .id             = AV_CODEC_ID_GSM,
 130     .init           = libgsm_encode_init,
 131     .encode2        = libgsm_encode_frame,
 132     .close          = libgsm_encode_close,
 133     .sample_fmts    = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
 134                                                      AV_SAMPLE_FMT_NONE },
 135     .long_name      = NULL_IF_CONFIG_SMALL("libgsm GSM"),
 136 };
 137
 138 AVCodec ff_libgsm_ms_encoder = {
 139     .name           = "libgsm_ms",
 140     .type           = AVMEDIA_TYPE_AUDIO,
 141     .id             = AV_CODEC_ID_GSM_MS,
 142     .init           = libgsm_encode_init,
 143     .encode2        = libgsm_encode_frame,
 144     .close          = libgsm_encode_close,
 145     .sample_fmts    = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
 146                                                      AV_SAMPLE_FMT_NONE },
 147     .long_name      = NULL_IF_CONFIG_SMALL("libgsm GSM Microsoft variant"),
 148 };
 149
 150 typedef struct LibGSMDecodeContext {
 151     AVFrame frame;
 152     struct gsm_state *state;
 153 } LibGSMDecodeContext;
 154
 155 static av_cold int libgsm_decode_init(AVCodecContext *avctx) {
 156     LibGSMDecodeContext *s = avctx->priv_data;
 157
 158     avctx->channels       = 1;
 159     avctx->channel_layout = AV_CH_LAYOUT_MONO;
 160     avctx->sample_rate    = 8000;
 161     avctx->sample_fmt     = AV_SAMPLE_FMT_S16;
 162
 163     s->state = gsm_create();
 164
 165     switch(avctx->codec_id) {
 166     case AV_CODEC_ID_GSM:
 167         avctx->frame_size  = GSM_FRAME_SIZE;
 168         avctx->block_align = GSM_BLOCK_SIZE;
 169         break;
 170     case AV_CODEC_ID_GSM_MS: {
 171         int one = 1;
 172         gsm_option(s->state, GSM_OPT_WAV49, &one);
 173         avctx->frame_size  = 2 * GSM_FRAME_SIZE;
 174         avctx->block_align = GSM_MS_BLOCK_SIZE;
 175         }
 176     }
 177
 178     avcodec_get_frame_defaults(&s->frame);
 179     avctx->coded_frame = &s->frame;
 180
 181     return 0;
 182 }
 183
 184 static av_cold int libgsm_decode_close(AVCodecContext *avctx) {
 185     LibGSMDecodeContext *s = avctx->priv_data;
 186
 187     gsm_destroy(s->state);
 188     s->state = NULL;
 189     return 0;
 190 }
 191
 192 static int libgsm_decode_frame(AVCodecContext *avctx, void *data,
 193                                int *got_frame_ptr, AVPacket *avpkt)
 194 {
 195     int i, ret;
 196     LibGSMDecodeContext *s = avctx->priv_data;
 197     uint8_t *buf = avpkt->data;
 198     int buf_size = avpkt->size;
 199     int16_t *samples;
 200
 201     if (buf_size < avctx->block_align) {
 202         av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
 203         return AVERROR_INVALIDDATA;
 204     }
 205
 206     /* get output buffer */
 207     s->frame.nb_samples = avctx->frame_size;
 208     if ((ret = ff_get_buffer(avctx, &s->frame)) < 0) {
 209         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 210         return ret;
 211     }
 212     samples = (int16_t *)s->frame.data[0];
 213
 214     for (i = 0; i < avctx->frame_size / GSM_FRAME_SIZE; i++) {
 215         if ((ret = gsm_decode(s->state, buf, samples)) < 0)
 216             return -1;
 217         buf     += GSM_BLOCK_SIZE;
 218         samples += GSM_FRAME_SIZE;
 219     }
 220
 221     *got_frame_ptr   = 1;
 222     *(AVFrame *)data = s->frame;
 223
 224     return avctx->block_align;
 225 }
 226
 227 static void libgsm_flush(AVCodecContext *avctx) {
 228     LibGSMDecodeContext *s = avctx->priv_data;
 229     int one = 1;
 230
 231     gsm_destroy(s->state);
 232     s->state = gsm_create();
 233     if (avctx->codec_id == AV_CODEC_ID_GSM_MS)
 234         gsm_option(s->state, GSM_OPT_WAV49, &one);
 235 }
 236
 237 AVCodec ff_libgsm_decoder = {
 238     .name           = "libgsm",
 239     .type           = AVMEDIA_TYPE_AUDIO,
 240     .id             = AV_CODEC_ID_GSM,
 241     .priv_data_size = sizeof(LibGSMDecodeContext),
 242     .init           = libgsm_decode_init,
 243     .close          = libgsm_decode_close,
 244     .decode         = libgsm_decode_frame,
 245     .flush          = libgsm_flush,
 246     .capabilities   = CODEC_CAP_DR1,
 247     .long_name      = NULL_IF_CONFIG_SMALL("libgsm GSM"),
 248 };
 249
 250 AVCodec ff_libgsm_ms_decoder = {
 251     .name           = "libgsm_ms",
 252     .type           = AVMEDIA_TYPE_AUDIO,
 253     .id             = AV_CODEC_ID_GSM_MS,
 254     .priv_data_size = sizeof(LibGSMDecodeContext),
 255     .init           = libgsm_decode_init,
 256     .close          = libgsm_decode_close,
 257     .decode         = libgsm_decode_frame,
 258     .flush          = libgsm_flush,
 259     .capabilities   = CODEC_CAP_DR1,
 260     .long_name      = NULL_IF_CONFIG_SMALL("libgsm GSM Microsoft variant"),
 261 };