get_iplayer Download Olympics In Chunks Tutorial

[Matt Davis]

On Aug 8 11:59:11 EDT 2012 dinkypumpkin wrote: 

>All the above is to be expected. Using --start leaves the output file in 
>an ugly state.  ffmpeg can power through.

>[mp4 @ 031FE020] Application provided invalid, non monotonically increasing dts >to muxer in stream 0: 1 >= 1 >av_interleaved_write_frame(): Invalid argument  >This should be eliminated by using the -ss argument of ffmpeg to skip 
>the head of the .flv file, where the timestamps are out of whack. 
>Without knowing what commands you used it's difficult to say where you 
>went wrong.  You may just need to increase the -ss value.

Thanks dinky, I started each file at -ss "00:00:04" and the conversion worked sort of, except now there is no audio and video 
for first four seconds? I also updated ffmpeg to the latest so not sure whether that made a difference.


On Aug 8 12:25:26 EDT 2012 MS wrote: 


>Did you follow my tutorial instructions for using ffmpeg accurately?

>e.g.

>ffmpeg -i DL_Chunk_01.mp4.flv -ss "00:00:00" -t "00:40:00"
>-vcodec copy -acodec copy Output_1.mp4

>Please note my use of -ss "00:00:00" above and in the tutorial for 
>re-muxing the first chunk even though that just specifies the start of 
>the video.

>Also the ffmpeg parameter order is important and must be as shown above 
>and in the tutorial. I had failures when I specified the -ss and -t 
>parameters before the -i inputfile.mp4.flv parameter.

>If neither of those fix your problem then you could try starting at -ss 
>"00:00:02" skipping the first 2 seconds and making absolutely sure that 
>your -t duration (DURATION NOT STOP TIME) is less than the length of 
>video you actually downloaded before the errors but that's all I can 
>think of.

Thanks, yes, followed your ffmpeg commands to the letter. What I'm not 100% sure of is how to accurately determine the duration, 
especially when I start cutting bits from the start etc.

Matt