/* * Interface to libgsm for gsm encoding/decoding * Copyright (c) 2005 Alban Bedel <albeu@free.fr> * Copyright (c) 2006, 2007 Michel Bardiaux <mbardiaux@mediaxim.be> * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * Interface to libgsm for gsm encoding/decoding */ // The idiosyncrasies of GSM-in-WAV are explained at http://kbs.cs.tu-berlin.de/~jutta/toast.html #include <gsm/gsm.h> #include "avcodec.h" #include "gsm.h" static av_cold int libgsm_encode_init(AVCodecContext *avctx) { if (avctx->channels > 1) { av_log(avctx, AV_LOG_ERROR, "Mono required for GSM, got %d channels\n", avctx->channels); return -1; } if (avctx->sample_rate != 8000) { av_log(avctx, AV_LOG_ERROR, "Sample rate 8000Hz required for GSM, got %dHz\n", avctx->sample_rate); if (avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL) return -1; } if (avctx->bit_rate != 13000 /* Official */ && avctx->bit_rate != 13200 /* Very common */ && avctx->bit_rate != 0 /* Unknown; a.o. mov does not set bitrate when decoding */ ) { av_log(avctx, AV_LOG_ERROR, "Bitrate 13000bps required for GSM, got %dbps\n", avctx->bit_rate); if (avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL) return -1; } avctx->priv_data = gsm_create(); if (!avctx->priv_data) goto error; switch(avctx->codec_id) { case CODEC_ID_GSM: avctx->frame_size = GSM_FRAME_SIZE; avctx->block_align = GSM_BLOCK_SIZE; break; case CODEC_ID_GSM_MS: { int one = 1; gsm_option(avctx->priv_data, GSM_OPT_WAV49, &one); avctx->frame_size = 2*GSM_FRAME_SIZE; avctx->block_align = GSM_MS_BLOCK_SIZE; } } avctx->coded_frame= avcodec_alloc_frame(); if (!avctx->coded_frame) goto error; return 0; error: libgsm_encode_close(); return -1; } static av_cold int libgsm_encode_close(AVCodecContext *avctx) { av_freep(&avctx->coded_frame); gsm_destroy(avctx->priv_data); avctx->priv_data = NULL; return 0; } static int libgsm_encode_frame(AVCodecContext *avctx, unsigned char *frame, int buf_size, void *data) { // we need a full block if(buf_size < avctx->block_align) return 0; switch(avctx->codec_id) { case CODEC_ID_GSM: gsm_encode(avctx->priv_data,data,frame); break; case CODEC_ID_GSM_MS: gsm_encode(avctx->priv_data,data,frame); gsm_encode(avctx->priv_data,((short*)data)+GSM_FRAME_SIZE,frame+32); } return avctx->block_align; } AVCodec ff_libgsm_encoder = { .name = "libgsm", .type = AVMEDIA_TYPE_AUDIO, .id = CODEC_ID_GSM, .init = libgsm_encode_init, .encode = libgsm_encode_frame, .close = libgsm_encode_close, .sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_S16,AV_SAMPLE_FMT_NONE}, .long_name = NULL_IF_CONFIG_SMALL("libgsm GSM"), }; AVCodec ff_libgsm_ms_encoder = { .name = "libgsm_ms", .type = AVMEDIA_TYPE_AUDIO, .id = CODEC_ID_GSM_MS, .init = libgsm_encode_init, .encode = libgsm_encode_frame, .close = libgsm_encode_close, .sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_S16,AV_SAMPLE_FMT_NONE}, .long_name = NULL_IF_CONFIG_SMALL("libgsm GSM Microsoft variant"), }; typedef struct LibGSMDecodeContext { AVFrame frame; struct gsm_state *state; } LibGSMDecodeContext; static av_cold int libgsm_decode_init(AVCodecContext *avctx) { LibGSMDecodeContext *s = avctx->priv_data; if (avctx->channels > 1) { av_log(avctx, AV_LOG_ERROR, "Mono required for GSM, got %d channels\n", avctx->channels); return -1; } if (!avctx->channels) avctx->channels = 1; if (!avctx->sample_rate) avctx->sample_rate = 8000; avctx->sample_fmt = AV_SAMPLE_FMT_S16; s->state = gsm_create(); switch(avctx->codec_id) { case CODEC_ID_GSM: avctx->frame_size = GSM_FRAME_SIZE; avctx->block_align = GSM_BLOCK_SIZE; break; case CODEC_ID_GSM_MS: { int one = 1; gsm_option(s->state, GSM_OPT_WAV49, &one); avctx->frame_size = 2 * GSM_FRAME_SIZE; avctx->block_align = GSM_MS_BLOCK_SIZE; } } avcodec_get_frame_defaults(&s->frame); avctx->coded_frame = &s->frame; return 0; } static av_cold int libgsm_decode_close(AVCodecContext *avctx) { LibGSMDecodeContext *s = avctx->priv_data; gsm_destroy(s->state); s->state = NULL; return 0; } static int libgsm_decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt) { int i, ret; LibGSMDecodeContext *s = avctx->priv_data; uint8_t *buf = avpkt->data; int buf_size = avpkt->size; int16_t *samples; if (buf_size < avctx->block_align) { av_log(avctx, AV_LOG_ERROR, "Packet is too small\n"); return AVERROR_INVALIDDATA; } /* get output buffer */ s->frame.nb_samples = avctx->frame_size; if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) { av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); return ret; } samples = (int16_t *)s->frame.data[0]; for (i = 0; i < avctx->frame_size / GSM_FRAME_SIZE; i++) { if ((ret = gsm_decode(s->state, buf, samples)) < 0) return -1; buf += GSM_BLOCK_SIZE; samples += GSM_FRAME_SIZE; } *got_frame_ptr = 1; *(AVFrame *)data = s->frame; return avctx->block_align; } static void libgsm_flush(AVCodecContext *avctx) { LibGSMDecodeContext *s = avctx->priv_data; int one = 1; gsm_destroy(s->state); s->state = gsm_create(); if (avctx->codec_id == CODEC_ID_GSM_MS) gsm_option(s->state, GSM_OPT_WAV49, &one); } AVCodec ff_libgsm_decoder = { .name = "libgsm", .type = AVMEDIA_TYPE_AUDIO, .id = CODEC_ID_GSM, .priv_data_size = sizeof(LibGSMDecodeContext), .init = libgsm_decode_init, .close = libgsm_decode_close, .decode = libgsm_decode_frame, .flush = libgsm_flush, .capabilities = CODEC_CAP_DR1, .long_name = NULL_IF_CONFIG_SMALL("libgsm GSM"), }; AVCodec ff_libgsm_ms_decoder = { .name = "libgsm_ms", .type = AVMEDIA_TYPE_AUDIO, .id = CODEC_ID_GSM_MS, .priv_data_size = sizeof(LibGSMDecodeContext), .init = libgsm_decode_init, .close = libgsm_decode_close, .decode = libgsm_decode_frame, .flush = libgsm_flush, .capabilities = CODEC_CAP_DR1, .long_name = NULL_IF_CONFIG_SMALL("libgsm GSM Microsoft variant"), };