ffmpeg fails when seeking in wtv file

[Mfouchi 1]

Hi,

I started this conversation in the Roku forum, but now that I see that it happens in iOS Safari as well, I'm not sure if its client specific, so I'll put it here.

 

When I am viewing a Recorded show in LiveTV, and it tries to transcode, ffmpeg throws errors when I try to skip ahead.  Specifically:

"Failed to compensate for timestamp delta of XXX"

It works properly when I play from the beginning and don't try to jump ahead.

 

This fails when I play from Roku3 and from iOS Safari, but it works properly when I play from Chrome on my PC.

I noticed that the ffmpeg commands are slightly different for each (see below)

ROKU (fail)
ffmpeg.exe -ss 00:16:27.000 -fflags +genpts -async 1 -vsync -1 -i file:"G:\Recorded TV\The Tonight Show Starring Jimmy Fallon_WDSUDT_2014_07_28_22_32_00.wtv" -map_metadata -1 -threads 2 -map 0:2 -map 0:0 -map -0:s -codec:v:0 libx264 -preset superfast -crf 23 -maxrate 4700000 -bufsize 9400000 -r 23.97602 -vsync vfr -profile:v high -level 41 -force_key_frames expr:gte(t,n_forced*7) -vf "scale=trunc(min(iw\,1920)/2)*2:trunc(min((iw/dar)\,1080)/2)*2" -copyts -flags -global_header -codec:a:0 aac -strict experimental -ac 2 -ab 128000 -af "adelay=1,aresample=async=1000,volume=2" -hls_time 7 -start_number 141 -hls_list_size 1440 -y "C:\Users\Fouchi\AppData\Roaming\MediaBrowser-Server\transcoding-temp\8e91c7320a58366da4e2d8e741a2554e.m3u8"

iOS (fail)
ffmpeg.exe -ss 00:10:37.000 -fflags +genpts -async 1 -vsync -1 -i file:"G:\Recorded TV\The Tonight Show Starring Jimmy Fallon_WDSUDT_2014_07_31_22_32_00.wtv" -map_metadata -1 -threads 2 -map 0:2 -map 0:0 -map -0:s -codec:v:0 libx264 -preset superfast -crf 23 -maxrate 1872000 -bufsize 3744000 -r 23.97602 -vsync vfr -profile:v baseline -level 3 -force_key_frames expr:gte(t,n_forced*7) -vf "scale=min(iw\,1280):trunc(ow/dar/2)*2" -copyts -flags -global_header -codec:a:0 aac -strict experimental -ac 2 -ab 128000 -af "adelay=1,aresample=async=1000,volume=2" -hls_time 7 -start_number 91 -hls_list_size 1440 -y "C:\Users\Fouchi\AppData\Roaming\MediaBrowser-Server\transcoding-temp\3744d3f76b931f719bda1fbe9ac34397.m3u8" 

CHROME (successful)
ffmpeg.exe -ss 00:13:23.248 -fflags +genpts -async 1 -vsync -1 -i file:"G:\Recorded TV\The Tonight Show Starring Jimmy Fallon_WDSUDT_2014_07_31_22_32_00.wtv" -map 0:2 -map 0:0 -map -0:s -vcodec libvpx -force_key_frames expr:gte(t,n_forced*5) -vf "scale=min(iw\,1280):trunc(ow/dar/2)*2" -speed 16 -quality good -profile:v 2 -slices 8 -crf 12 -maxrate:v 3872000 -bufsize:v (3872000*2) -b:v 3872000 -r 23.97602 -vsync vfr -map_metadata -1 -threads 2 -acodec libvorbis -ac 2 -ab 128000 -af "aresample=async=1000,volume=2" -y "C:\Users\Fouchi\AppData\Roaming\MediaBrowser-Server\transcoding-temp\f489e3e9e93db247fcfc147f05305bef.webm" 

Among other things, I noticed that Chrome adds a fraction of a second to the -ss flag. (Although, when I test this on command line, and add this fraction to the Roku or iOS params, it still gets errors)

Also, I noticed that Roku thinks the file is 1080, but its actually 720.   It also has this error in the log file "[mpeg2video @ 02805b40] Invalid frame dimensions 0x0.".  Not sure if that's has something to do with it.

 

I've attached the full transcode log files for each case as well.

 

I'm running:

  Windows 7 x64

  MB Server Version 3.0.5326.13255  (just released)

  ServerWMC 1.0.0.36  build: 1154

 

This happens for several different wtv files, not just this one.

 

Thanks for your help.

Marc

CHROME-(Success)-transcode-8efed521-06fe-4a5d-8f9d-2a75b1dff5e1.txt

iOS-transcode-8d3bd535-6583-4665-8ad9-91ba4e5bce01.txt

ROKU-transcode-a9cfe923-0abc-4338-826f-0a07aef72b32.txt

Edited August 2, 2014 by Mfouchi

[Mfouchi 1]

Hi @krustyreturns,

Would this be under your jurisdiction since its dealing with LiveTV?  I'm not sure where the ffmpeg command gets issued.  Is ServerWMC responsible for kicking off the transcoding?

Thanks,

Marc

[Luke 37028]

No it's not. Thanks for reporting.