Problem with ffmpeg or the source?

[Andy Bircumshaw]

On 18/12/2010, at 8:46am, Shevek wrote:
> ...
> Of the Nigel Slater files in my archive eps 1 to 6 were originally
> processed with r25557 and ep 7 with a later version
> 
> Eps 1 to 5 are showing no problem at all and eps 6 & 7 exhibit the
> issue. This to me points to the source, not ffmpeg.
> 
> As all 7 eps are still on iPlayer I will re-download them all using
> both r25557 and r26401 and post results

Instead of re-downloading them all with the different versions (i.e. twice), I think you can just use `get_iplayer --raw` and then transcode by hand using different versions of ffmpeg.

If you seen differences between r25557 and r26401 you can then try with r25979 (the SVN version halfway between them) and see whether the change occurred before or after then, and continue splitting SVN revisions until you find the one that causes the problem. I think this is called "regression testing".

Having downloaded once with "--raw" you'll have the original file on your PC to work with and can keep trying the different versions of ffmpeg more easily.

aB.