1/* 2 * gsm 06.10 decoder 3 * Copyright (c) 2010 Reimar Döffinger <Reimar.Doeffinger@gmx.de> 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22/** 23 * @file 24 * GSM decoder 25 */ 26 27#include "config_components.h" 28 29#include "libavutil/channel_layout.h" 30#include "avcodec.h" 31#include "codec_internal.h" 32#include "get_bits.h" 33#include "internal.h" 34#include "msgsmdec.h" 35 36#include "gsmdec_template.c" 37 38static av_cold int gsm_init(AVCodecContext *avctx) 39{ 40 av_channel_layout_uninit(&avctx->ch_layout); 41 avctx->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO; 42 if (!avctx->sample_rate) 43 avctx->sample_rate = 8000; 44 avctx->sample_fmt = AV_SAMPLE_FMT_S16; 45 46 switch (avctx->codec_id) { 47 case AV_CODEC_ID_GSM: 48 avctx->frame_size = GSM_FRAME_SIZE; 49 avctx->block_align = GSM_BLOCK_SIZE; 50 break; 51 case AV_CODEC_ID_GSM_MS: 52 avctx->frame_size = 2 * GSM_FRAME_SIZE; 53 if (!avctx->block_align) 54 avctx->block_align = GSM_MS_BLOCK_SIZE; 55 else 56 if (avctx->block_align < MSN_MIN_BLOCK_SIZE || 57 avctx->block_align > GSM_MS_BLOCK_SIZE || 58 (avctx->block_align - MSN_MIN_BLOCK_SIZE) % 3) { 59 av_log(avctx, AV_LOG_ERROR, "Invalid block alignment %d\n", 60 avctx->block_align); 61 return AVERROR_INVALIDDATA; 62 } 63 } 64 65 return 0; 66} 67 68static int gsm_decode_frame(AVCodecContext *avctx, AVFrame *frame, 69 int *got_frame_ptr, AVPacket *avpkt) 70{ 71 int res; 72 GetBitContext gb; 73 const uint8_t *buf = avpkt->data; 74 int buf_size = avpkt->size; 75 int16_t *samples; 76 77 if (buf_size < avctx->block_align) { 78 av_log(avctx, AV_LOG_ERROR, "Packet is too small\n"); 79 return AVERROR_INVALIDDATA; 80 } 81 82 /* get output buffer */ 83 frame->nb_samples = avctx->frame_size; 84 if ((res = ff_get_buffer(avctx, frame, 0)) < 0) 85 return res; 86 samples = (int16_t *)frame->data[0]; 87 88 switch (avctx->codec_id) { 89 case AV_CODEC_ID_GSM: 90 init_get_bits(&gb, buf, buf_size * 8); 91 if (get_bits(&gb, 4) != 0xd) 92 av_log(avctx, AV_LOG_WARNING, "Missing GSM magic!\n"); 93 res = gsm_decode_block(avctx, samples, &gb, GSM_13000); 94 if (res < 0) 95 return res; 96 break; 97 case AV_CODEC_ID_GSM_MS: 98 res = ff_msgsm_decode_block(avctx, samples, buf, 99 (GSM_MS_BLOCK_SIZE - avctx->block_align) / 3); 100 if (res < 0) 101 return res; 102 } 103 104 *got_frame_ptr = 1; 105 106 return avctx->block_align; 107} 108 109static void gsm_flush(AVCodecContext *avctx) 110{ 111 GSMContext *s = avctx->priv_data; 112 memset(s, 0, sizeof(*s)); 113} 114 115#if CONFIG_GSM_DECODER 116const FFCodec ff_gsm_decoder = { 117 .p.name = "gsm", 118 .p.long_name = NULL_IF_CONFIG_SMALL("GSM"), 119 .p.type = AVMEDIA_TYPE_AUDIO, 120 .p.id = AV_CODEC_ID_GSM, 121 .priv_data_size = sizeof(GSMContext), 122 .init = gsm_init, 123 FF_CODEC_DECODE_CB(gsm_decode_frame), 124 .flush = gsm_flush, 125 .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF, 126 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE, 127}; 128#endif 129#if CONFIG_GSM_MS_DECODER 130const FFCodec ff_gsm_ms_decoder = { 131 .p.name = "gsm_ms", 132 .p.long_name = NULL_IF_CONFIG_SMALL("GSM Microsoft variant"), 133 .p.type = AVMEDIA_TYPE_AUDIO, 134 .p.id = AV_CODEC_ID_GSM_MS, 135 .priv_data_size = sizeof(GSMContext), 136 .init = gsm_init, 137 FF_CODEC_DECODE_CB(gsm_decode_frame), 138 .flush = gsm_flush, 139 .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF, 140 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE, 141}; 142#endif 143