[Libav-user] av_samples_fill_arrays and memory

Bruce Wheaton bruce at spearmorgan.com
Sun Apr 28 21:22:43 CEST 2013


On Apr 27, 2013, at 10:44 AM, Brad O'Hearne wrote:

> On Apr 26, 2013, at 1:45 PM, Bruce Wheaton <bruce at spearmorgan.com> wrote:
> 
>> It may be that your source of dest buffers, if not from ffmpeg, are not correctly aligned.
> 
> To the best of my knowledge, the source data is aligned, exactly as needed. Reasons for saying so:  
> 
> 1. The meta-data on the QTSampleBuffer coming over indicates that this is so. 

Why don't you just check the addresses of the data planes and know it? It's 2 minutes to check a few times.
> 
> 2. The same code / source data being used with the FLTP sample format / AAC encoder works perfect with a S16 sample format / ADPCM_SWF encoder. An alignment problem with the source data most likely would cause a problem in both scenarios. 

Not true at all. The specific code to deal with each codec type will be radically different - undefined, remember.

This isn't a alignment question as in 'off by one sample', it's an alignment issue as in vector operations won't work right.

Bruce


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