mirror of https://github.com/FFmpeg/FFmpeg.git
Nidhi Makhijani
11 years ago
committed by
Diego Biurrun
parent
8b0dd4942a
commit
b4edbe9a0e
3 changed files with 158 additions and 116 deletions
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/*
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* Interface to libgsm for GSM decoding |
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* Copyright (c) 2005 Alban Bedel <albeu@free.fr> |
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* Copyright (c) 2006, 2007 Michel Bardiaux <mbardiaux@mediaxim.be> |
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* |
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* This file is part of Libav. |
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* |
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* Libav is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* Libav is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with Libav; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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/**
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* @file |
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* Interface to libgsm for GSM decoding |
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*/ |
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// The idiosyncrasies of GSM-in-WAV are explained at http://kbs.cs.tu-berlin.de/~jutta/toast.html
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#include "config.h" |
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#if HAVE_GSM_H |
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#include <gsm.h> |
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#else |
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#include <gsm/gsm.h> |
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#endif |
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#include "libavutil/channel_layout.h" |
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#include "libavutil/common.h" |
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#include "avcodec.h" |
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#include "internal.h" |
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#include "gsm.h" |
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typedef struct LibGSMDecodeContext { |
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struct gsm_state *state; |
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} LibGSMDecodeContext; |
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static av_cold int libgsm_decode_init(AVCodecContext *avctx) { |
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LibGSMDecodeContext *s = avctx->priv_data; |
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avctx->channels = 1; |
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avctx->channel_layout = AV_CH_LAYOUT_MONO; |
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avctx->sample_rate = 8000; |
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avctx->sample_fmt = AV_SAMPLE_FMT_S16; |
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s->state = gsm_create(); |
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switch(avctx->codec_id) { |
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case AV_CODEC_ID_GSM: |
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avctx->frame_size = GSM_FRAME_SIZE; |
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avctx->block_align = GSM_BLOCK_SIZE; |
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break; |
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case AV_CODEC_ID_GSM_MS: { |
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int one = 1; |
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gsm_option(s->state, GSM_OPT_WAV49, &one); |
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avctx->frame_size = 2 * GSM_FRAME_SIZE; |
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avctx->block_align = GSM_MS_BLOCK_SIZE; |
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} |
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} |
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return 0; |
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} |
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static av_cold int libgsm_decode_close(AVCodecContext *avctx) { |
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LibGSMDecodeContext *s = avctx->priv_data; |
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gsm_destroy(s->state); |
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s->state = NULL; |
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return 0; |
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} |
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static int libgsm_decode_frame(AVCodecContext *avctx, void *data, |
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int *got_frame_ptr, AVPacket *avpkt) |
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{ |
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int i, ret; |
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LibGSMDecodeContext *s = avctx->priv_data; |
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AVFrame *frame = data; |
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uint8_t *buf = avpkt->data; |
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int buf_size = avpkt->size; |
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int16_t *samples; |
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if (buf_size < avctx->block_align) { |
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av_log(avctx, AV_LOG_ERROR, "Packet is too small\n"); |
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return AVERROR_INVALIDDATA; |
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} |
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/* get output buffer */ |
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frame->nb_samples = avctx->frame_size; |
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if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) { |
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av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); |
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return ret; |
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} |
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samples = (int16_t *)frame->data[0]; |
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for (i = 0; i < avctx->frame_size / GSM_FRAME_SIZE; i++) { |
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if ((ret = gsm_decode(s->state, buf, samples)) < 0) |
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return -1; |
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buf += GSM_BLOCK_SIZE; |
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samples += GSM_FRAME_SIZE; |
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} |
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*got_frame_ptr = 1; |
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return avctx->block_align; |
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} |
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static void libgsm_flush(AVCodecContext *avctx) { |
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LibGSMDecodeContext *s = avctx->priv_data; |
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int one = 1; |
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gsm_destroy(s->state); |
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s->state = gsm_create(); |
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if (avctx->codec_id == AV_CODEC_ID_GSM_MS) |
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gsm_option(s->state, GSM_OPT_WAV49, &one); |
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} |
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AVCodec ff_libgsm_decoder = { |
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.name = "libgsm", |
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.long_name = NULL_IF_CONFIG_SMALL("libgsm GSM"), |
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.type = AVMEDIA_TYPE_AUDIO, |
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.id = AV_CODEC_ID_GSM, |
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.priv_data_size = sizeof(LibGSMDecodeContext), |
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.init = libgsm_decode_init, |
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.close = libgsm_decode_close, |
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.decode = libgsm_decode_frame, |
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.flush = libgsm_flush, |
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.capabilities = CODEC_CAP_DR1, |
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}; |
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AVCodec ff_libgsm_ms_decoder = { |
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.name = "libgsm_ms", |
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.long_name = NULL_IF_CONFIG_SMALL("libgsm GSM Microsoft variant"), |
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.type = AVMEDIA_TYPE_AUDIO, |
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.id = AV_CODEC_ID_GSM_MS, |
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.priv_data_size = sizeof(LibGSMDecodeContext), |
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.init = libgsm_decode_init, |
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.close = libgsm_decode_close, |
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.decode = libgsm_decode_frame, |
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.flush = libgsm_flush, |
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.capabilities = CODEC_CAP_DR1, |
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}; |
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