>> >> When I am opening a file I call avformat_open_input, then after that I >> call avformat_find_stream_info, and I am timing those calls: >> >> 'avformat_open_input': 9.7970 seconds >> 'avformat_find_stream_info': 0.1080 seconds >> >> So for me the problem seems to be avformat_open_input. My testfiles >> are all around that range, maybe +-2 sec > > You mentioned that you read the files using http urls, so isn't there the > download time included in the values you measure for avformat_open_input? > Yeah sure, it will have to get the data first, but I am wondering if that amount of data can be reduced, because 10 sec seems quite long to me for opening, but those probesize etc don't seem to make a difference.
On the other hand, once I have opened, and I seek to a spot later in the file, it is so fast it is almost instant.. so that's why I wondered if the amount of data analyzed/download on initial opening can be reduced... > In my case I fill a memory buffer first and then feed that to the avformat > functions. > > Nevertheless I will time these two functions again. I always assumed that the > time is lost in avformat_find_stream_info and not in avformat_open_input, but > may be my assumption was wrong. > yeah please let me know your findings, am curious to hear... >> >> As I mentioned before, changine probesize/analyzeduration from 5000000 >> to 5000 doesn't seem show any visible effect (just ranging within the >> usual fluctuations of the above timings) >> >> Is that what you experienced too? > > if I reduce probesize/analyzeduration it does not get faster, but at some > point it fails to recognize the streams. At 100000 it does fail most of the > time (mpegts h264/aac). > for me I can often go down as low as 5000 (or at least 10000) before it starts failing.. but the timing doesn't seem to change really... > Which is why I would love to configure all possible settings which can be set > before these functions are called. > yeah me too... cheers, Bjoern _______________________________________________ Libav-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/libav-user
