/* * gsm 06.10 decoder * Copyright (c) 2010 Reimar Döffinger <Reimar.Doeffinger@gmx.de> * * This file is part of Libav. * * Libav 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. * * Libav 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 Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * GSM decoder */ #include "libavutil/channel_layout.h" #include "avcodec.h" #include "get_bits.h" #include "internal.h" #include "msgsmdec.h" #include "gsmdec_template.c" static av_cold int gsm_init(AVCodecContext *avctx) { avctx->channels = 1; avctx->channel_layout = AV_CH_LAYOUT_MONO; avctx->sample_rate = 8000; avctx->sample_fmt = AV_SAMPLE_FMT_S16; switch (avctx->codec_id) { case AV_CODEC_ID_GSM: avctx->frame_size = GSM_FRAME_SIZE; avctx->block_align = GSM_BLOCK_SIZE; break; case AV_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 *got_frame_ptr, AVPacket *avpkt) { AVFrame *frame = data; int res; GetBitContext gb; const 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 */ frame->nb_samples = avctx->frame_size; if ((res = ff_get_buffer(avctx, frame, 0)) < 0) { av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); return res; } samples = (int16_t *)frame->data[0]; switch (avctx->codec_id) { case AV_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 AV_CODEC_ID_GSM_MS: res = ff_msgsm_decode_block(avctx, samples, buf); if (res < 0) return res; } *got_frame_ptr = 1; return avctx->block_align; } static void gsm_flush(AVCodecContext *avctx) { GSMContext *s = avctx->priv_data; memset(s, 0, sizeof(*s)); } AVCodec ff_gsm_decoder = { .name = "gsm", .long_name = NULL_IF_CONFIG_SMALL("GSM"), .type = AVMEDIA_TYPE_AUDIO, .id = AV_CODEC_ID_GSM, .priv_data_size = sizeof(GSMContext), .init = gsm_init, .decode = gsm_decode_frame, .flush = gsm_flush, .capabilities = CODEC_CAP_DR1, }; AVCodec ff_gsm_ms_decoder = { .name = "gsm_ms", .long_name = NULL_IF_CONFIG_SMALL("GSM Microsoft variant"), .type = AVMEDIA_TYPE_AUDIO, .id = AV_CODEC_ID_GSM_MS, .priv_data_size = sizeof(GSMContext), .init = gsm_init, .decode = gsm_decode_frame, .flush = gsm_flush, .capabilities = CODEC_CAP_DR1, };