Impala Documentation

bool Impala::Core::Stream::RgbDataSrcLavc_old::InitStreams ( ) [inline, private]

Definition at line 401 of file RgbDataSrcLavc_old.h.

References mFormatCtx, Impala::Core::Stream::RgbDataSrc::mSrcName, Impala::Core::Stream::RgbDataSrc::mStreamCount, mVideoStream, and mVideoStreamIndex.

Referenced by Init().

00402     {
00403         mStreamCount = mFormatCtx->nb_streams;
00404         mVideoStreamIndex = -1;
00405         mVideoStream = 0;
00406 
00407         // find the first video stream 
00408         for (int i = 0; i < mStreamCount; i++)
00409         {
00410             if (mFormatCtx->streams[i]->codec->codec_type 
00411                                                     == CODEC_TYPE_VIDEO)
00412             {
00413                 if (mVideoStreamIndex >= 0)
00414                     throw (LAVCException("Multiple video streams found in: " 
00415                                 + mSrcName, 0));
00416 
00417                 mVideoStreamIndex = i;
00418                 mVideoStream = mFormatCtx->streams[i];
00419             }
00420         }
00421         if (mVideoStream == 0) 
00422             throw LAVCException("Could not find video stream in: " 
00423                                 + mSrcName, 0);
00424 
00425         // collect video stream info
00426         mVideoDuration = mVideoStream->duration; // number of (time) fractions
00427         const AVRational videoTimeBase = 
00428             mVideoStream->time_base; // time fraction duration (seconds)
00429         mTimeBaseNum = videoTimeBase.num;
00430         mTimeBaseDen = videoTimeBase.den;
00431         mDuration = ceil(
00432             double(mVideoDuration) * mTimeBaseNum / mTimeBaseDen
00433             ); // rounded up (number of seconds)
00434         mDurationSec = mDuration;
00435         mDurationHour = mDurationSec / 3600;
00436         mDurationSec %= 3600;
00437         mDurationMin = mDurationSec / 60;
00438         mDurationSec %= 60;
00439 
00440         // collect frame info
00441         mFrameRateNum = mVideoStream->r_frame_rate.num;
00442         mFrameRateDen = mVideoStream->r_frame_rate.den;
00443         const double fractionsPerSec = double(mTimeBaseDen) / mTimeBaseNum;
00444         const double secondsPerFrame = double(mFrameRateDen) / mFrameRateNum;
00445         const double fractionsPerFrame = fractionsPerSec * secondsPerFrame;
00446         const double frameCount = mVideoDuration / fractionsPerFrame;
00447         mFrameCountCalculated = ceil(frameCount);
00448         ILOG_DEBUG("Frame count estimate based on video duration: " << 
00449             mFrameCountCalculated);
00450 
00451         return true;
00452     }