Aegisub/aegisub/audio_provider_lavc.cpp

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// Copyright (c) 2005-2006, Rodrigo Braz Monteiro, Fredrik Mellbin
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// * Neither the name of the Aegisub Group nor the names of its contributors
// may be used to endorse or promote products derived from this software
// without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// -----------------------------------------------------------------------------
//
// AEGISUB
//
// Website: http://aegisub.cellosoft.com
// Contact: mailto:zeratul@cellosoft.com
//
///////////
// Headers
#ifdef WITH_FFMPEG
#ifdef WIN32
#define EMULATE_INTTYPES
#endif
#include <wx/wxprec.h>
/* avcodec.h uses INT64_C in a *single* place. This prolly breaks on Win32,
* but, well. Let's at least fix it for Linux.
*
#define __STDC_CONSTANT_MACROS 1
#include <stdint.h>
* - done in posix/defines.h
*/
extern "C" {
#include <ffmpeg/avcodec.h>
#include <ffmpeg/avformat.h>
}
#include "mkv_wrap.h"
#include "lavc_file.h"
#include "audio_provider_lavc.h"
#include "lavc_file.h"
#include "utils.h"
#include "options.h"
///////////////
// Constructor
LAVCAudioProvider::LAVCAudioProvider(wxString _filename)
: lavcfile(NULL), codecContext(NULL), rsct(NULL), buffer(NULL)
{
try {
#if 0
/* since seeking currently is likely to be horribly broken with two
* providers accessing the same stream, this is disabled for now.
*/
LAVCVideoProvider *vpro_lavc = dynamic_cast<LAVCVideoProvider *>(vpro);
if (vpro_lavc) {
lavcfile = vpro->lavcfile->AddRef();
filename = vpro_lavc->GetFilename();
} else {
#endif
lavcfile = LAVCFile::Create(_filename);
filename = _filename;
#if 0
}
#endif
audStream = -1;
for (int i = 0; i < lavcfile->fctx->nb_streams; i++) {
codecContext = lavcfile->fctx->streams[i]->codec;
if (codecContext->codec_type == CODEC_TYPE_AUDIO) {
stream = lavcfile->fctx->streams[i];
audStream = i;
break;
}
}
if (audStream == -1) {
codecContext = NULL;
throw _T("Could not find an audio stream");
}
AVCodec *codec = avcodec_find_decoder(codecContext->codec_id);
if (!codec) {
codecContext = NULL;
throw _T("Could not find a suitable audio decoder");
}
if (avcodec_open(codecContext, codec) < 0)
throw _T("Failed to open audio decoder");
/* aegisub currently supports mono only, so always resample */
sample_rate = Options.AsInt(_T("Audio Sample Rate"));
if (!sample_rate)
sample_rate = codecContext->sample_rate;
channels = 1;
bytes_per_sample = 2;
rsct = audio_resample_init(1, codecContext->channels, sample_rate, codecContext->sample_rate);
if (!rsct)
throw _T("Failed to initialize resampling");
resample_ratio = (float)sample_rate / (float)codecContext->sample_rate;
double length = (double)stream->duration * av_q2d(stream->time_base);
num_samples = (int64_t)(length * sample_rate);
buffer = (int16_t *)malloc(AVCODEC_MAX_AUDIO_FRAME_SIZE);
if (!buffer)
throw _T("Out of memory");
} catch (...) {
Destroy();
throw;
}
}
LAVCAudioProvider::~LAVCAudioProvider()
{
Destroy();
}
void LAVCAudioProvider::Destroy()
{
if (buffer)
free(buffer);
if (rsct)
audio_resample_close(rsct);
if (codecContext)
avcodec_close(codecContext);
if (lavcfile)
lavcfile->Release();
}
void LAVCAudioProvider::GetAudio(void *buf, int64_t start, int64_t count)
{
int16_t *_buf = (int16_t *)buf;
int64_t _count = num_samples - start;
if (count < _count)
_count = count;
if (_count < 0)
_count = 0;
memset(_buf + _count, 0, (count - _count) << 1);
AVPacket packet;
while (_count > 0 && av_read_frame(lavcfile->fctx, &packet) >= 0) {
while (packet.stream_index == audStream) {
int bytesout = 0, samples;
if (avcodec_decode_audio(codecContext, buffer, &bytesout, packet.data, packet.size) < 0)
throw _T("Failed to decode audio");
if (bytesout == 0)
break;
samples = bytesout >> 1;
if (rsct) {
if ((int64_t)(samples * resample_ratio / codecContext->channels) > _count)
samples = (int64_t)(_count / resample_ratio * codecContext->channels);
samples = audio_resample(rsct, _buf, buffer, samples / codecContext->channels);
assert(samples <= _count);
} else {
/* currently dead code, rsct != NULL because we're resampling for mono */
if (samples > _count)
samples = _count;
memcpy(_buf, buffer, samples << 1);
}
_buf += samples;
_count -= samples;
break;
}
av_free_packet(&packet);
}
}
#endif