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VideoTexture: fix video capture lagging when CPU is busy. This problem was caused by special frame handling that was appropriate for video streaming but not for video capture: drift compensation and no frame skipping. Disable that for video capture to take into account the realtime nature of video.

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This commit is contained in:
Benoit Bolsee
2010-03-28 17:50:45 +00:00
parent 8ba96eb1ae
commit a99d584008
2 changed files with 20 additions and 7 deletions
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22
source/gameengine/VideoTexture/VideoFFmpeg.cpp
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@@ -56,7 +56,7 @@ m_frame(NULL), m_frameDeinterlaced(NULL), m_frameRGB(NULL), m_imgConvertCtx(NULL
m_deinterlace(false), m_preseek(0), m_videoStream(-1), m_baseFrameRate(25.0),
m_lastFrame(-1), m_eof(false), m_externTime(false), m_curPosition(-1), m_startTime(0),
m_captWidth(0), m_captHeight(0), m_captRate(0.f), m_isImage(false),
m_isThreaded(false), m_stopThread(false), m_cacheStarted(false)
m_isThreaded(false), m_isStreaming(false), m_stopThread(false), m_cacheStarted(false)
{
// set video format
m_format = RGB24;
@@ -298,6 +298,7 @@ int VideoFFmpeg::openStream(const char *filename, AVInputFormat *inputFormat, AV
*/
void *VideoFFmpeg::cacheThread(void *data)
{
static int count=0;
VideoFFmpeg* video = (VideoFFmpeg*)data;
// holds the frame that is being decoded
CacheFrame *currentFrame = NULL;
@@ -306,6 +307,8 @@ void *VideoFFmpeg::cacheThread(void *data)
int frameFinished = 0;
double timeBase = av_q2d(video->m_formatCtx->streams[video->m_videoStream]->time_base);
int64_t startTs = video->m_formatCtx->streams[video->m_videoStream]->start_time;
long pts;
if (startTs == AV_NOPTS_VALUE)
startTs = 0;
@@ -396,6 +399,7 @@ void *VideoFFmpeg::cacheThread(void *data)
// move frame to queue, this frame is necessarily the next one
video->m_curPosition = (long)((cachePacket->packet.dts-startTs) * (video->m_baseFrameRate*timeBase) + 0.5);
currentFrame->framePosition = video->m_curPosition;
pts = (long)((cachePacket->packet.pts-startTs) * (video->m_baseFrameRate*timeBase) + 0.5);
pthread_mutex_lock(&video->m_cacheMutex);
BLI_addtail(&video->m_frameCacheBase, currentFrame);
pthread_mutex_unlock(&video->m_cacheMutex);
@@ -544,8 +548,10 @@ void VideoFFmpeg::openFile (char * filename)
#endif
)
{
// the file is in fact a streaming source, prevent seeking
// the file is in fact a streaming source, treat as cam to prevent seeking
m_isFile = false;
// but it's not handled exactly like a camera.
m_isStreaming = true;
// for streaming it is important to do non blocking read
m_formatCtx->flags |= AVFMT_FLAG_NONBLOCK;
}
@@ -811,12 +817,12 @@ void VideoFFmpeg::calcImage (unsigned int texId, double ts)
// close the file as we don't need it anymore
release();
}
} else if (!m_isFile)
} else if (m_isStreaming)
{
// we didn't get a frame and we are streaming, this may be due to
// a delay in the network or because we are getting the frame too fast.
// In the later case, shift time by a small amount to compensate for a drift
m_startTime += 0.01;
m_startTime += 0.001;
}
}
}
@@ -878,14 +884,18 @@ AVFrame *VideoFFmpeg::grabFrame(long position)
}
// for streaming, always return the next frame,
// that's what grabFrame does in non cache mode anyway.
if (!m_isFile || frame->framePosition == position)
if (m_isStreaming || frame->framePosition == position)
{
return frame->frame;
}
if (frame->framePosition > position)
// for cam, skip old frames to keep image realtime.
// There should be no risk of clock drift since it all happens on the same CPU
if (frame->framePosition > position)
{
// this can happen after rewind if the seek didn't find the first frame
// the frame in the buffer is ahead of time, just leave it there
return NULL;
}
// this frame is not useful, release it
pthread_mutex_lock(&m_cacheMutex);
BLI_remlink(&m_frameCacheBase, frame);

5
source/gameengine/VideoTexture/VideoFFmpeg.h
View File

@@ -61,7 +61,7 @@ static inline AVCodecContext* get_codec_from_stream(AVStream* stream)
#include "VideoBase.h"
#define CACHE_FRAME_SIZE 5
#define CACHE_FRAME_SIZE 10
#define CACHE_PACKET_SIZE 30
// type VideoFFmpeg declaration
@@ -153,6 +153,9 @@ protected:
/// is image loading done in a separate thread?
bool m_isThreaded;
/// is streaming or camera?
bool m_isStreaming;
/// keep last image name
STR_String m_imageName;