[Ffmpeg-devel-irc] ffmpeg.log.20130923

[burek]

[00:14] <chinatsu> hello, i've been trying to make a video from an image sequence, but i don't seem to have much luck.. i'm using windows, and this is the command i'm using: ffmpeg.exe -f image2 -i image-%07d.png -r 30 output.avi
[00:17] <chinatsu> i do get output, but it only results in a very short video, 567ms
[00:18] <chinatsu> i'm trying to input 329 frames, though..
[00:18] <blakvoid> hello! how come the screenshot command no longer works!! ffmpeg -ss 00:31:00 -vframes 1 -i "test.mkv" -y -f image2 screenshot1.png results in a vframe error, any ideas?
[00:26] <chinatsu> turns out i had forgotten a few frames so it stopped the sequence..
[04:05] <intelikey> what is this error about >>> ffmpeg: symbol lookup error: ffmpeg: undefined symbol: ffm_nopts
[04:09] <intelikey> hello ?
[04:19] Last message repeated 1 time(s).
[04:20] <Zutara> Hi. I'm trying to convert a MKV to MP4 so my PS3 can recognize the file. This is the problem I'm running into: http://pastebin.com/63NYjbXc
[04:24] <klaxa> file might be broken, you are also not using ffmpeg but the fork avconv
[04:27] <Zutara> How can I fix the damaged MKV?
[04:37] <Zutara> Nevermind, found a script for it in the Plex forums. Thanks for the informative link. :D
[09:37] <Kingsy> anyone around? I was wondering what it means when you import media into a project and "transcode" it? I assume it means change the format of the media?
[11:56] <xlinkz0> how can I use the ffmpeg tool to cut accurate duration segments while stream copying?
[12:08] <mittens> is it possible for ffmpeg to capture live streams from justin.tv etc?
[12:16] <saste> xlinkz0, you can't
[12:17] <xlinkz0> saste: xuggler can..
[12:18] <xlinkz0> and it is using ffmpeg :\
[12:23] <saste> xlinkz0, did you read segment documentation?
[12:23] <xlinkz0> you mean seek?
[12:23] <saste> xlinkz0, no i mean what i wrote
[12:24] <saste> you need to cut segments at key-frame boundaries
[12:24] <saste> if the key-frames are not placed at exact boundaries, you can't cut at non-key frames, or you get invalid segments
[12:24] <saste> if you have audio segments, that should not be a problem
[12:25] <saste> and when transcoding, you can use the ffmpeg application to force key-frames at exact intervals
[12:25] <xlinkz0> saste: i need to cut video only segments, i understand the starting frame needs to be a keyframe but does the ending one need to be a keyframe aswell?
[12:26] <xlinkz0> i can live with starting on a keyframe but ending on one is too much extra video already..
[12:26] <saste> xlinkz0, the ending frame must be the last frame, or the last non-key frame before the next key-frame one
[12:26] <xlinkz0> saste: can you point me to the segment documentation that you talked about?
[12:27] <saste> xlinkz0, man ffmpeg-formats, or docs on website
[12:34] <xlinkz0> saste: so if I start cutting on timestamp 00:10:00 which is a keyframe, and I want a 3 second video but there's no keyframe at 00:10:03 but there is one at 00:10:04 there is no way I can cut just to 00:10:03 without transcoding?
[12:47] <saste> xlinkz0, what's your exact goal?
[12:48] <saste> do you want to cut a single segment, or segment all the video?
[12:49] <saste> in the first case you can use -ss 10 -t 3
[12:49] <saste> check also the doc in the faq, which addresses the seeking issue (seek is not exact)
[12:57] <xlinkz0> saste: i want to cut a single segment
[12:57] <xlinkz0> i have read the seeking documentation
[12:58] <xlinkz0> but my problem is that the duration is also affected by this
[12:58] <xlinkz0> for example i tell ffmpeg to cut a segment of 2.4 seconds and the resulting segment is 3.6 seconds long
[13:17] <saste> xlinkz0, is the starting point correct?
[13:17] <simonsimcity> Hi, all
[13:18] <xlinkz0> saste: does it matter? ffmpeg goes to the nearest i-frame anyway
[13:18] <simonsimcity> I try to combine two videos (vob) and get a bunch of "buffer underflow" errors ... in the output, the sound is quite broken.
[13:18] <simonsimcity> Here's a pastebin: http://pastebin.com/HkuazC7C
[13:18] <saste> xlink0: https://trac.ffmpeg.org/wiki/Seeking%20with%20FFmpeg
[13:19] <xlinkz0> saste: i read that , i'm not interested in accurate seeking, i'm interested in accure duration of segment..
[13:20] <xlinkz0> i don't care what the start timestamp is really, as long as the duration is exactly what i specified
[13:23] <saste> -t duration is usually accurate, depending on your definition of "accuracy"
[13:24] <xlinkz0> saste: http://codepad.org/O6wsJSe1
[13:24] <xlinkz0> the resulting video file has 3.6 seconds duration
[13:26] <saste> xlink0: ffprobe -show_entries packet=pts_time,duration_time -of compact test.mp4?
[13:27] <xlinkz0> saste: http://codepad.org/nkH5GZ20
[13:28] <saste> xlinkz0, unexpected behavior, can you try a more recent version of ffmpeg
[13:29] <xlinkz0> built on Aug  8 2013 13:17:06 with gcc 4.4.5 (Debian 4.4.5-8)
[13:29] <xlinkz0> ok i'll rebuild
[13:29] <saste> xlink0: http://thread.gmane.org/gmane.comp.video.ffmpeg.user/48033
[13:31] <saste> no, wrong link ^
[13:31] <xlinkz0> oh someone submitted this bug report today?
[13:31] <xlinkz0> so it is a bug?
[13:54] <simonsimcity> What's the source of a "frame sync error"? Got quite some of them here ...
[13:54] <simonsimcity> http://pastebin.com/L8Rwfhcx
[14:13] <vl4kn0> Hi, I'm trying to synchronize audio and video after decoding and this is the printout of AVPacket->pts for both audio and video streams: http://fpaste.org/41522/ what do I do when most of the video pts are AV_NOPTS_VALUE?
[14:26] <xlinkz0> saste: same with head
[14:26] <xlinkz0> i assume --depth 1 is head..
[14:48] <Bor0> if I were to implement a callback feature on ffplay, let's say when status is updated to STATUS_PLAYER_SEEK I want to callback a fn that the user has specified
[14:48] <Bor0> I tried something like status |= STATUS_PLAYER_SEEK; callback_fn(...);
[14:49] <Bor0> but this pauses the main thread and then ffplay goes wild
[14:49] <Bor0> what would be a good implementation to do this? I also considered threads but that did a lot of crashes
[15:02] <simonsimcity> Can anyone possibly help me? :( I get "Header missing" when trying to combine two videos ... converting one stand-alone, works.
[15:02] <simonsimcity> http://pastebin.com/VrJK2iBV
[15:03] <simonsimcity> If I try to copy the streams (both input and output-files are MPEG) I get a buffer underflow error ....
[15:03] <simonsimcity> http://pastebin.com/Rbp7uv7B
[15:03] <simonsimcity> Tried this using FFMpeg v1.2.x and v2.0.1 ...
[15:12] <simonsimcity> Just a question on that ...
[15:13] <simonsimcity> On one of the clips I try to merge, video and audio are switched (audio is on 0 and video on 1, for the rest, it's vv.)
[17:22] <matej_k> hey, could anyone tell me what exactly ff_h264_find_frame_end does? maybe some pointers to specification?
[19:33] <matej_k> can I feed 264 decoder single slice from PAFF stream in frame based multi threaded decoding mode?
[19:33] <matej_k> or does it have to be entire frame (i.e. both slices) at the same time
[20:19] <CentRookie> How important do you think is -pix_fmt yuv420p for older web players
[20:27] <JEEB> CentRookie, I think that's the only thing that works with most things, big exceptions being flash's software decoder (MainConcept-licensed) that supports 4:2:2 as well, and some things that use a relatively new libavcodec as their decoder
[20:30] <JEEB> if you need any kind of hardware decoding compatibility, or compatibility at all, 4:2:0 YCbCr (colloquially "YUV" although YUV really just was an analog thing and has nothing to do with the digital YCbCr) is your only choice
[20:30] <JEEB> of course, many encoders either only support it or select it by default
[20:31] <JEEB> so it might be an implicit conversion, see the ffmpeg cli log for details of what ffmpeg is doing
[21:00] <CentRookie> i see
[22:13] <smjd> what could cause output audio track to play at a lower rate?
[22:24] <BallsDeep> When I'm decoding DTS to WAV (or any other format to to WAV) , should I chose a "32" bit depth? Does it matter whether I choose 16, 24 or 32? FFMPEG want to default to "16".
[22:25] <BallsDeep> When I'm decoding DTS to WAV (or any other format to WAV) , should I chose a "32" bit depth? Does it matter whether I choose 16, 24 or 32? FFMPEG want to default to "16".
[23:39] <BallsDeep> When I'm decoding DTS to WAV, should I chose a "32" bit depth? Does it matter whether I choose 16, 24 or 32? FFMPEG defaults to "16".
[23:43] <sacarasc> Use the same as the input.
[23:44] <BallsDeep> I'll use "24" bit then. Thanks!
[00:00] --- Tue Sep 24 2013