// H.264 動画で TimeScale が4倍精度になってるか調べる
public bool IsTimeScaleFour()
{
int c;
int count = 0;
long[] dts = new long[4];
if (video_codec_context.codec_id != 28) // H.264 でないので関係ない
{
return(false);
}
while ((c = AVCodecAPI.av_read_frame(p_avformat_context, p_packet)) >= 0)
{
PacketContainer container = new PacketContainer(p_packet);
if (container.packet.stream_index == video_stream_index)
{
dts[count] = container.packet.dts;
++count;
}
container.Destruct();
if (count >= dts.Length)
{
break;
}
}
AVCodecAPI.av_seek_frame(p_avformat_context, video_stream_index, 0, 0);
return(dts[1] - dts[0] == 1001 && dts[2] - dts[1] == 1001 && dts[3] - dts[2] == 2002);
}
public void FixIllegalFrameRate()
{
int c;
int count = 0;
long[] dts = new long[50];
while ((c = AVCodecAPI.av_read_frame(p_avformat_context, p_packet)) >= 0)
{
PacketContainer container = new PacketContainer(p_packet);
if (container.packet.stream_index == video_stream_index)
{
dts[count] = container.packet.dts;
++count;
}
container.Destruct();
if (count >= dts.Length)
{
break;
}
}
double average_dts = 0.0;
for (int i = 5; i < count - 1; ++i) // 最初の5フレームは捨てる
{
average_dts += dts[i + 1] - dts[i];
}
average_dts /= (double)(count - 1 - 5);
if (average_dts > 0)
{
double new_frame_rate_d = (double)video_stream.time_base.den / video_stream.time_base.num / average_dts;
int new_frame_rate = (int)(new_frame_rate_d * 1000);
int new_frame_scale = 1000;
new_frame_rate = 30;
new_frame_scale = 1;
for (int i = 0; i < key_frame_list_.Count; ++i)
{
key_frame_list_[i] = (int)((double)key_frame_list_[i] * new_frame_rate * video_scale_
/ ((double)new_frame_scale * video_rate_));
}
video_rate_ = new_frame_rate;
video_scale_ = new_frame_scale;
}
AVCodecAPI.av_seek_frame(p_avformat_context, video_stream_index, 0, 0);
}
/// <summary>
/// 動画ファイルを開く
/// </summary>
/// <param name="filename">ファイルパス</param>
/// <param name="width">動画サイズを固定する場合の幅（負の値を指定した場合は元の動画サイズになる）</param>
/// <param name="height">動画サイズを固定する場合の高さ（負の値を指定した場合は元の動画サイズになる）</param>
/// <param name="memory_size">使用するメモリサイズ（MB）（負の値を指定した場合は自動設定）</param>
public void Open(string filename, int video_width, int video_height, int memory_size)
{
OpenCodec(filename);
fixed_video_width_ = video_width;
fixed_video_height_ = video_height;
video_rate_ = video_stream.r_frame_rate.num;
video_scale_ = video_stream.r_frame_rate.den;
p_frame = AVCodecAPI.avcodec_alloc_frame();
p_frame_rgb = AVCodecAPI.avcodec_alloc_frame();
p_packet = AVCodecAPI.av_malloc(Marshal.SizeOf(new AVPacket()));
long last_dts = 0;
int c = 0;
bool is_first = true;
int start_frame = 0;
while (c >= 0)
{
if (!is_first)
{
AVCodecAPI.av_seek_frame(p_avformat_context, video_stream_index, last_dts + 1, 0);
}
while ((c = AVCodecAPI.av_read_frame(p_avformat_context, p_packet)) >= 0)
{
PacketContainer container = new PacketContainer(p_packet);
if (container.packet.stream_index == video_stream_index)
{
last_dts = container.packet.dts;
key_dts_list_.Add(last_dts);
key_frame_list_.Add(DtsToVideoFrame(last_dts));
if (is_first)
{
is_first = false;
start_frame = key_frame_list_[key_frame_list_.Count - 1];
}
break;
}
container.Destruct();
}
}
AVCodecAPI.av_seek_frame(p_avformat_context, video_stream_index, 0, 0);
if (IsTimeScaleFour())
{
video_scale_ *= 4;
for (int i = 0; i < key_frame_list_.Count; ++i)
{
key_frame_list_[i] /= 4;
}
}
if (video_rate_ / video_scale_ > 60)
{
FixIllegalFrameRate();
}
if (HasVideo)
{
if (memory_size <= 0)
{
memory_size = Math.Min(Math.Max(BufferContainer.GetMemorySize() / (1024 * 1024) - 500, 100), 500); // 最小100MB、最大500MB
}
video_buffer_manager_ = new VideoBufferManager(this, FrameLength, memory_size * 1024 * 1024 / VideoPictureBufferSize, start_frame);
}
if (HasAudio)
{
audio_buffer_manager_ = new AudioBufferManager();
audio_buffer_manager_.SetDataLength(AudioSampleRate * AudioChannel
* AudioBytesPerSample * format_context.duration / 1000000);
p_audio_buffer = Marshal.AllocHGlobal(audio_temp_buffer_size_);
audio_priority_times_ = 10;
}
StartDecoding();
}