yading@10: /*
yading@10:  * gsm 06.10 decoder
yading@10:  * Copyright (c) 2010 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * GSM decoder
yading@10:  */
yading@10: 
yading@10: #include "libavutil/channel_layout.h"
yading@10: #include "avcodec.h"
yading@10: #include "get_bits.h"
yading@10: #include "internal.h"
yading@10: #include "msgsmdec.h"
yading@10: 
yading@10: #include "gsmdec_template.c"
yading@10: 
yading@10: static av_cold int gsm_init(AVCodecContext *avctx)
yading@10: {
yading@10:     avctx->channels       = 1;
yading@10:     avctx->channel_layout = AV_CH_LAYOUT_MONO;
yading@10:     if (!avctx->sample_rate)
yading@10:         avctx->sample_rate = 8000;
yading@10:     avctx->sample_fmt     = AV_SAMPLE_FMT_S16;
yading@10: 
yading@10:     switch (avctx->codec_id) {
yading@10:     case AV_CODEC_ID_GSM:
yading@10:         avctx->frame_size  = GSM_FRAME_SIZE;
yading@10:         avctx->block_align = GSM_BLOCK_SIZE;
yading@10:         break;
yading@10:     case AV_CODEC_ID_GSM_MS:
yading@10:         avctx->frame_size  = 2 * GSM_FRAME_SIZE;
yading@10:         avctx->block_align = GSM_MS_BLOCK_SIZE;
yading@10:     }
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int gsm_decode_frame(AVCodecContext *avctx, void *data,
yading@10:                             int *got_frame_ptr, AVPacket *avpkt)
yading@10: {
yading@10:     AVFrame *frame = data;
yading@10:     int res;
yading@10:     GetBitContext gb;
yading@10:     const uint8_t *buf = avpkt->data;
yading@10:     int buf_size = avpkt->size;
yading@10:     int16_t *samples;
yading@10: 
yading@10:     if (buf_size < avctx->block_align) {
yading@10:         av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
yading@10:         return AVERROR_INVALIDDATA;
yading@10:     }
yading@10: 
yading@10:     /* get output buffer */
yading@10:     frame->nb_samples = avctx->frame_size;
yading@10:     if ((res = ff_get_buffer(avctx, frame, 0)) < 0)
yading@10:         return res;
yading@10:     samples = (int16_t *)frame->data[0];
yading@10: 
yading@10:     switch (avctx->codec_id) {
yading@10:     case AV_CODEC_ID_GSM:
yading@10:         init_get_bits(&gb, buf, buf_size * 8);
yading@10:         if (get_bits(&gb, 4) != 0xd)
yading@10:             av_log(avctx, AV_LOG_WARNING, "Missing GSM magic!\n");
yading@10:         res = gsm_decode_block(avctx, samples, &gb);
yading@10:         if (res < 0)
yading@10:             return res;
yading@10:         break;
yading@10:     case AV_CODEC_ID_GSM_MS:
yading@10:         res = ff_msgsm_decode_block(avctx, samples, buf);
yading@10:         if (res < 0)
yading@10:             return res;
yading@10:     }
yading@10: 
yading@10:     *got_frame_ptr = 1;
yading@10: 
yading@10:     return avctx->block_align;
yading@10: }
yading@10: 
yading@10: static void gsm_flush(AVCodecContext *avctx)
yading@10: {
yading@10:     GSMContext *s = avctx->priv_data;
yading@10:     memset(s, 0, sizeof(*s));
yading@10: }
yading@10: 
yading@10: #if CONFIG_GSM_DECODER
yading@10: AVCodec ff_gsm_decoder = {
yading@10:     .name           = "gsm",
yading@10:     .type           = AVMEDIA_TYPE_AUDIO,
yading@10:     .id             = AV_CODEC_ID_GSM,
yading@10:     .priv_data_size = sizeof(GSMContext),
yading@10:     .init           = gsm_init,
yading@10:     .decode         = gsm_decode_frame,
yading@10:     .flush          = gsm_flush,
yading@10:     .capabilities   = CODEC_CAP_DR1,
yading@10:     .long_name      = NULL_IF_CONFIG_SMALL("GSM"),
yading@10: };
yading@10: #endif
yading@10: #if CONFIG_GSM_MS_DECODER
yading@10: AVCodec ff_gsm_ms_decoder = {
yading@10:     .name           = "gsm_ms",
yading@10:     .type           = AVMEDIA_TYPE_AUDIO,
yading@10:     .id             = AV_CODEC_ID_GSM_MS,
yading@10:     .priv_data_size = sizeof(GSMContext),
yading@10:     .init           = gsm_init,
yading@10:     .decode         = gsm_decode_frame,
yading@10:     .flush          = gsm_flush,
yading@10:     .capabilities   = CODEC_CAP_DR1,
yading@10:     .long_name      = NULL_IF_CONFIG_SMALL("GSM Microsoft variant"),
yading@10: };
yading@10: #endif