[FFmpeg-devel] TrueHD decoder bug or something else is wrong

Konstantin Dimitrov kosio.dimitrov
Sun Jul 19 17:52:07 CEST 2009

hi All,

i have 3 very small TrueHD samples and the raw PCM (stereo, 16bit,
48kHz) sources from which they are created (taken from Blu-ray disc),
you can find them here:

http://rapidshare.com/files/257596582/thd_samples.tar.bz2.html (size: 144Kb)

and the files are as follows:

sample0[1-3]_stereo_16bit_48khz.thd : the TrueHD sample
sample0[1-3]_stereo_16bit_48khz.pcm : raw PCM source - both Left and
Right channel
sample0[1-3]_stereo_16bit_48khz_left.pcm : raw PCM source - Left channel only
sample0[1-3]_stereo_16bit_48khz_right.pcm : raw PCM source - Right channel only

for example when i use FFmpeg version SVN-r19371 with
sample02_stereo_16bit_48khz.thd i get:

[truehd @ 0xf92870]Lossless check failed - expected 92, calculated bf.

and as a result Left channel is decoded byte-by-byte identical with
the source, but there are some different bytes in the Right channel
compared to the source.

the problem with other two samples is similar, but with them both
channels are decoded not byte-by-byte identical with the source and
there are several different bytes.

so, as the subject says, does some bug in the TrueHD decoder cause the
problem or something else is wrong like corrupted TrueHD stream?

thank you,

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