| /* |
| * gsm 06.10 decoder |
| * Copyright (c) 2010 Reimar Döffinger <Reimar.Doeffinger@gmx.de> |
| * |
| * 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 |
| * GSM decoder |
| */ |
| |
| #include "avcodec.h" |
| #include "get_bits.h" |
| #include "msgsmdec.h" |
| |
| #include "gsmdec_template.c" |
| |
| static av_cold int gsm_init(AVCodecContext *avctx) |
| { |
| avctx->channels = 1; |
| if (!avctx->sample_rate) |
| avctx->sample_rate = 8000; |
| avctx->sample_fmt = AV_SAMPLE_FMT_S16; |
| |
| 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: |
| avctx->frame_size = 2 * GSM_FRAME_SIZE; |
| avctx->block_align = GSM_MS_BLOCK_SIZE; |
| } |
| |
| return 0; |
| } |
| |
| static int gsm_decode_frame(AVCodecContext *avctx, void *data, |
| int *data_size, AVPacket *avpkt) |
| { |
| int res; |
| GetBitContext gb; |
| const uint8_t *buf = avpkt->data; |
| int buf_size = avpkt->size; |
| int16_t *samples = data; |
| int frame_bytes = 2 * avctx->frame_size; |
| |
| if (*data_size < frame_bytes) |
| return -1; |
| *data_size = 0; |
| if(buf_size < avctx->block_align) |
| return AVERROR_INVALIDDATA; |
| |
| switch (avctx->codec_id) { |
| case CODEC_ID_GSM: |
| init_get_bits(&gb, buf, buf_size * 8); |
| if (get_bits(&gb, 4) != 0xd) |
| av_log(avctx, AV_LOG_WARNING, "Missing GSM magic!\n"); |
| res = gsm_decode_block(avctx, samples, &gb); |
| if (res < 0) |
| return res; |
| break; |
| case CODEC_ID_GSM_MS: |
| res = ff_msgsm_decode_block(avctx, samples, buf); |
| if (res < 0) |
| return res; |
| } |
| *data_size = frame_bytes; |
| return avctx->block_align; |
| } |
| |
| AVCodec ff_gsm_decoder = { |
| "gsm", |
| AVMEDIA_TYPE_AUDIO, |
| CODEC_ID_GSM, |
| sizeof(GSMContext), |
| gsm_init, |
| NULL, |
| NULL, |
| gsm_decode_frame, |
| .long_name = NULL_IF_CONFIG_SMALL("GSM"), |
| }; |
| |
| AVCodec ff_gsm_ms_decoder = { |
| "gsm_ms", |
| AVMEDIA_TYPE_AUDIO, |
| CODEC_ID_GSM_MS, |
| sizeof(GSMContext), |
| gsm_init, |
| NULL, |
| NULL, |
| gsm_decode_frame, |
| .long_name = NULL_IF_CONFIG_SMALL("GSM Microsoft variant"), |
| }; |