Split examiner parts off decoder.

1 files changed, 138 insertions, 0 deletions

diff --git a/src/lib/ffmpeg.cc b/src/lib/ffmpeg.cc
new file mode 100644
index 000000000..0d897abfa
--- /dev/null
+++ b/src/lib/ffmpeg.cc
@@ -0,0 +1,138 @@
+/*
+    Copyright (C) 2013 Carl Hetherington <cth@carlh.net>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program 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 General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+extern "C" {
+#include <libavcodec/avcodec.h>
+#include <libavformat/avformat.h>
+#include <libswscale/swscale.h>
+#include <libpostproc/postprocess.h>
+}
+#include "ffmpeg.h"
+#include "ffmpeg_content.h"
+#include "exceptions.h"
+
+#include "i18n.h"
+
+using std::string;
+using std::stringstream;
+using boost::shared_ptr;
+
+boost::mutex FFmpeg::_mutex;
+
+FFmpeg::FFmpeg (boost::shared_ptr<const FFmpegContent> c)
+	: _ffmpeg_content (c)
+	, _format_context (0)
+	, _frame (0)
+	, _video_stream (-1)
+	, _video_codec_context (0)
+	, _video_codec (0)
+	, _audio_codec_context (0)
+	, _audio_codec (0)
+{
+	setup_general ();
+	setup_video ();
+	setup_audio ();
+}
+
+FFmpeg::~FFmpeg ()
+{
+	boost::mutex::scoped_lock lm (_mutex);
+	
+	if (_audio_codec_context) {
+		avcodec_close (_audio_codec_context);
+	}
+
+	if (_video_codec_context) {
+		avcodec_close (_video_codec_context);
+	}
+
+	av_free (_frame);
+	
+	avformat_close_input (&_format_context);
+}
+
+void
+FFmpeg::setup_general ()
+{
+	av_register_all ();
+
+	if (avformat_open_input (&_format_context, _ffmpeg_content->file().string().c_str(), 0, 0) < 0) {
+		throw OpenFileError (_ffmpeg_content->file().string ());
+	}
+
+	if (avformat_find_stream_info (_format_context, 0) < 0) {
+		throw DecodeError (_("could not find stream information"));
+	}
+
+	/* Find video stream */
+
+	for (uint32_t i = 0; i < _format_context->nb_streams; ++i) {
+		AVStream* s = _format_context->streams[i];
+		if (s->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
+			_video_stream = i;
+		}
+	}
+
+	if (_video_stream < 0) {
+		throw DecodeError (N_("could not find video stream"));
+	}
+
+	_frame = avcodec_alloc_frame ();
+	if (_frame == 0) {
+		throw DecodeError (N_("could not allocate frame"));
+	}
+}
+
+void
+FFmpeg::setup_video ()
+{
+	boost::mutex::scoped_lock lm (_mutex);
+	
+	_video_codec_context = _format_context->streams[_video_stream]->codec;
+	_video_codec = avcodec_find_decoder (_video_codec_context->codec_id);
+
+	if (_video_codec == 0) {
+		throw DecodeError (_("could not find video decoder"));
+	}
+
+	if (avcodec_open2 (_video_codec_context, _video_codec, 0) < 0) {
+		throw DecodeError (N_("could not open video decoder"));
+	}
+}
+
+void
+FFmpeg::setup_audio ()
+{
+	boost::mutex::scoped_lock lm (_mutex);
+	
+	if (!_ffmpeg_content->audio_stream ()) {
+		return;
+	}
+
+	_audio_codec_context = _format_context->streams[_ffmpeg_content->audio_stream()->id]->codec;
+	_audio_codec = avcodec_find_decoder (_audio_codec_context->codec_id);
+
+	if (_audio_codec == 0) {
+		throw DecodeError (_("could not find audio decoder"));
+	}
+
+	if (avcodec_open2 (_audio_codec_context, _audio_codec, 0) < 0) {
+		throw DecodeError (N_("could not open audio decoder"));
+	}
+}