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 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/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 43static av_cold int libgsm_encode_close(AVCodecContext *avctx) { 44 gsm_destroy(avctx->priv_data); 45 avctx->priv_data = NULL; 46 return 0; 47} 48 49static 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", 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); 59 if (avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL) 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 %dbps\n", 66 avctx->bit_rate); 67 if (avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL) 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; 84 avctx->block_align = GSM_MS_BLOCK_SIZE; 85 } 86 } 87 88 return 0; 89error: 90 libgsm_encode_close(avctx); 91 return -1; 92} 93 94static 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) 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 119AVCodec 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, 128 AV_SAMPLE_FMT_NONE }, 129}; 130#endif 131#if CONFIG_LIBGSM_MS_ENCODER 132AVCodec 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, 141 AV_SAMPLE_FMT_NONE }, 142}; 143#endif 144 145typedef struct LibGSMDecodeContext { 146 struct gsm_state *state; 147} LibGSMDecodeContext; 148 149static av_cold int libgsm_decode_init(AVCodecContext *avctx) { 150 LibGSMDecodeContext *s = avctx->priv_data; 151 152 avctx->channels = 1; 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; 157 158 s->state = gsm_create(); 159 160 switch(avctx->codec_id) { 161 case AV_CODEC_ID_GSM: 162 avctx->frame_size = GSM_FRAME_SIZE; 163 avctx->block_align = GSM_BLOCK_SIZE; 164 break; 165 case AV_CODEC_ID_GSM_MS: { 166 int one = 1; 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; 170 } 171 } 172 173 return 0; 174} 175 176static av_cold int libgsm_decode_close(AVCodecContext *avctx) { 177 LibGSMDecodeContext *s = avctx->priv_data; 178 179 gsm_destroy(s->state); 180 s->state = NULL; 181 return 0; 182} 183 184static int libgsm_decode_frame(AVCodecContext *avctx, void *data, 185 int *got_frame_ptr, AVPacket *avpkt) 186{ 187 int i, ret; 188 LibGSMDecodeContext *s = avctx->priv_data; 189 AVFrame *frame = data; 190 uint8_t *buf = avpkt->data; 191 int buf_size = avpkt->size; 192 int16_t *samples; 193 194 if (buf_size < avctx->block_align) { 195 av_log(avctx, AV_LOG_ERROR, "Packet is too small\n"); 196 return AVERROR_INVALIDDATA; 197 } 198 199 /* get output buffer */ 200 frame->nb_samples = avctx->frame_size; 201 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) 202 return ret; 203 samples = (int16_t *)frame->data[0]; 204 205 for (i = 0; i < avctx->frame_size / GSM_FRAME_SIZE; i++) { 206 if ((ret = gsm_decode(s->state, buf, samples)) < 0) 207 return -1; 208 buf += GSM_BLOCK_SIZE; 209 samples += GSM_FRAME_SIZE; 210 } 211 212 *got_frame_ptr = 1; 213 214 return avctx->block_align; 215} 216 217static void libgsm_flush(AVCodecContext *avctx) { 218 LibGSMDecodeContext *s = avctx->priv_data; 219 int one = 1; 220 221 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); 225} 226 227#if CONFIG_LIBGSM_DECODER 228AVCodec ff_libgsm_decoder = { 229 .name = "libgsm", 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, 239}; 240#endif 241#if CONFIG_LIBGSM_MS_DECODER 242AVCodec ff_libgsm_ms_decoder = { 243 .name = "libgsm_ms", 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, 253}; 254#endif 255