Aegisub/aegisub/lavc_keyframes.cpp

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// Copyright (c) 2007, 2points
// 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
#include "lavc_keyframes.h"
///////////////
// Constructor
LAVCKeyFrames::LAVCKeyFrames(const wxString& filename)
: file(0), codecContext(0), codec(0), stream(0), frame(0),
streamN(-1) {
// Open LAVCFile
file = LAVCFile::Create(filename);
// Find video stream
for (unsigned int i = 0; i < file->fctx->nb_streams; ++i) {
codecContext = file->fctx->streams[i]->codec;
codecContext->skip_frame = AVDISCARD_NONKEY;
codecContext->workaround_bugs = FF_BUG_AUTODETECT;
if (codecContext->codec_type == CODEC_TYPE_VIDEO) {
stream = file->fctx->streams[i];
stream->discard = AVDISCARD_NONKEY;
streamN = i;
break;
}
}
if (streamN == -1) throw _T("Could not find a video stream");
// Find codec
codec = avcodec_find_decoder(codecContext->codec_id);
if (!codec) throw _T("Could not find suitable video decoder");
// Open codec
int result = avcodec_open(codecContext, codec);
if (result < 0) throw _T("Failed to open video decoder");
// Allocate frame
frame = avcodec_alloc_frame();
}
//////////////
// Destructor
LAVCKeyFrames::~LAVCKeyFrames() {
if (frame) av_free((void*) frame);
if (codec && codecContext) avcodec_close(codecContext);
if (file) file->Release();
}
////////////////////////////
// Parse file for keyframes
wxArrayInt LAVCKeyFrames::GetKeyFrames() {
wxArrayInt keyframes;
AVPacket packet;
register unsigned int frameN = 0; // Number of parsed frames
while (av_read_frame(file->fctx, &packet) >= 0) {
// Check if packet is part of video stream
if (packet.stream_index == streamN) {
// Increment number of passed frames
++frameN;
// Decode frame
int frameFinished;
avcodec_decode_video(codecContext, frame, &frameFinished, packet.data, packet.size);
// Success?
if(frameFinished) {
if (frame->key_frame)
// Aegisub starts counting at frame 0, so the result must be
// parsed frames - 1
keyframes.Add(frameN - 1);
// Free packet
av_free_packet(&packet);
}
}
}
return keyframes;
}