[Ffmpeg-devel-irc] ffmpeg.log.20130323

[burek]

[11:20] <onto> Hi! I have created a simple program to save video streams from /dev/vide0 as ppm files. Is the api for capturing audio + saving similar?
[11:41] <cas> Hi, I try to use ffmpeg to build a simple streamer, i use `ffmpeg -f alsa -i hw:0 -f wav pipe:1` which works nice if I output to a file and use ctrl-c to quit. But when I use parts of the output and write them away it's unreadable data
[11:41] <cas> I guess I miss some header parts
[11:42] <cas> Any ideas how I can use parts of this output and re-encode them?
[12:46] <onto1> so I now have a working program that captures audio but how do I save the audio stream into a file (say as a wav, or raw pcm)?
[13:17] <robin1423> impossible to compile ffmpeg on debian 6.0 squeeze :( I'm too bad
[13:17] <robin1423> but no problem on Ubuntu \o/
[14:49] <Washu> Hi, is there a way to concat all files in a directory without putting all their filenames in a txt file first?
[15:51] <xlinkz0> can anyone help me with cross compiling?
[15:52] <Mavrik> for which platform?
[16:12] <xlinkz0> Mavrik, i'm trying to use the windows build helpers
[16:13] <xlinkz0> i've gotten this far : http://codepad.org/VXE6INAp
[16:13] <Mavrik> what you posted makes no sense, neither is connected to ffmpeg
[16:13] <Mavrik> what are you trying to do?
[16:15] <xlinkz0> cross compile ffmpeg for windows
[16:15] <xlinkz0> it's the final output of the windows helper script
[16:15] <xlinkz0> http://ffmpeg.org/trac/ffmpeg/wiki/CrossCompilingForWindows
[16:15] <xlinkz0> this wiki points to https://github.com/rdp/ffmpeg-windows-build-helpers which i am using
[16:17] <xlinkz0> basically all i want to do is compile ffplay for windows, but with some of my modifications
[16:17] <Mavrik> ugh
[16:18] <Mavrik> yeah, I'm looking at that script
[16:18] <Mavrik> It's compiling half a world and then some
[16:18] <Mavrik> xlinkz0, but the error is very clear you know
[16:18] <Mavrik> 2013-03-23 16:39:09 ERROR 404: Not Found.
[16:18] <Mavrik> --2013-03-23 16:39:09--  http://www.mpfr.org/mpfr-current/mpfr-3.1.1.tar.xz
[16:18] <Mavrik> it's trying to download mpfr-current and it's the wrong URL.
[16:18] <xlinkz0> yep.. i'm guessing i can't use that script right?
[16:19] <xlinkz0> do you compile your ffmpeg on windows?
[16:19] <xlinkz0> or rather, for windows
[16:20] <Mavrik> xlinkz0, why don't you just fix the URL?
[16:21] <Mavrik> probably the version number changed
[16:21] <xlinkz0> wouldn't i have to restart the script all over?
[16:21] <Mavrik> probably
[16:22] <onto> Hi! I have the following code to record from /dev/dsp1 (http://pastebin.ca/2338857) but how do I save the audio stream as a wav file?
[16:23] <xlinkz0> i think it would be easier to get the zeranoe dev build , mingw and compile ffplay that way
[16:25] <Mavrik> onto, um, WAV is just raw sound data with a header
[16:25] <Mavrik> onto, so write the WAV header and then just write the buffers you're getting from decode_audio to file
[16:25] <Mavrik> https://ccrma.stanford.edu/courses/422/projects/WaveFormat/
[16:25] <Mavrik> you can read most of those parameters from the input context
[16:26] <onto> Mavrik: but where are the "buffers" is it in AVFrame->data[0] ?
[16:28] <Mavrik> onto, yeah
[16:28] <Mavrik> onto, look at the decode audio example in ffmpeg docs: https://github.com/FFmpeg/FFmpeg/blob/master/doc/examples/decoding_encoding.c
[16:28] <Mavrik> onto, it does pretty much what you're trying to do
[16:29] <Mavrik> (except it doesn't create WAV header)
[16:29] <onto> Mavrik: Thank you! I'll look into it :)
[16:29] <Mavrik> as you can see you need to call "av_samples_get_buffer_size" to get size of actual data in AVFrame buffer
[16:29] <Mavrik> and then just grab that from data[0g
[17:01] <onto> Mavrik: just to see what's actually happening, I have directly written the data to a file (without headers) -- is it possible to play it using ffplay?
[17:11] <Mavrik> onto, uhm, probably
[17:11] <Mavrik> look for pcm input format / options
[17:18] <onto1> Mavrik: ok
[17:21] <onto1> Mavrik: Thank you so much! It works! :D
[18:15] <rnissl> Hi, I've recently upgraded ffmpeg and it seams that AVCODEC_MAX_AUDIO_FRAME_SIZE is gone. How shall client programs be updated that formerly used that constant?
[00:00] --- Sun Mar 24 2013