Hello Carl,
Thanks for the response !
Yes, there is no free lunch.
You will have to find values that work for you and are smaller than
the default.
The problem is that I'm working with a RTP multicast streams; not static
files. So what I see happening a lot is the following:
* I set values that are smaller than the default
* The values work in most cases; however some times they do not. When
this happens; what is the best course of action ? Can I just
increase the values and try again without wasting too much time ?
How do you know you have gathered "all the basic information" of
a transport stream?
(There was a sample stream for which -probesize 2G was not enough
so we increased the range for the option.)
I guess I could have been clearer, sorry. What I meant was; is there a
way of telling FFMPEG to imminently stop analyzing the stream (even if
the "probesize" number of bytes haven't been used up yet) once it
gathers enough information about the stream ?
So for instance if the *probesize *is set to 4MB; if my understanding is
correct FFMPEG will finish avformat_find_stream_info/avfromat_open_input
only when it reads all 4MB of data. Isn't there a way to stop it from
reading the rest if for instance, only 1MB was enough to get the
metadata from the stream ?
So I guess what I'm trying to say is; I would like it to stop analyzing
the stream:
* In case of audio, as soon as it detects the codec type, sample rate
and number of channels.
* In case of video, as soon as it detects the codec type, video
resolution and "extradata" in case of H264/H265
Best regards,
Nikola
On 17-May-17 10:05, Carl Eugen Hoyos wrote:
2017-05-15 11:09 GMT+02:00 Nikola Spiric<[email protected]>:
I tried reducing "probesize" and "analyzeduration" parameters with
mixed results. Sometimes it indeed does speed up mentioned function
calls; however they often just result in the functions failing (i.e. they
don't get enough data to provide me with all the information I need).
Yes, there is no free lunch.
You will have to find values that work for you and are smaller than
the default.
So my question is: Is there a way to tell FFMPEG to stop analyzing the
stream once it gathers all the basic information (video width/height,
h.264/HEVC extra data or audio sample rate/number of channels) ?
How do you know you have gathered "all the basic information" of
a transport stream?
(There was a sample stream for which -probesize 2G was not enough
so we increased the range for the option.)
I really need a way of speeding up these two function calls (5
seconds is not acceptable for my needs).
5 seconds seem extremely long on current hardware.
Carl Eugen
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