Hi,
Is it ok to make a fate-test out of it?
Well, are you asking if it is allowed to include that sample in the
source distribution for
testing purpose?
Personally, I don't care... but I'm not the copyright holder of the
broadcasted material who can grant permission on it.
On 2015/06/03 15:55, Luca Barbato wrote:
On 03/06/15 07:40, nu774 wrote:
Let me explain on this patch.
Issue:
------
AAC decoder incorectly decode this sample (taken from Japanese DVB):
https://dl.dropboxusercontent.com/u/76042064/5.1ch_PCE_issue.aac
Every once in 0.5 sec or so, glitches are generated. It is audible, and
also you can easily spot them on spectrogram of the decoded result.
It seems that quite many (all?) of 5.1ch DVB audio in Japan trigger
simular issue.
Is it ok to make a fate-test out of it?
Explanation:
------------
This ADTS file contains ordinary 5.1ch AAC with non-zero
channel_configuration(6). However, it also contains PCE every once in
0.5 sec or so.
Channel elemnents and element_instance_tag(ID) are like this:
[SCE][0], [CPE][2], [CPE][4], [LFE][5] (*1)
When AACdec sees ADTS frame header, it assigns channels using default
channel configuration for 5.1ch. It is like this:
[SCE][0], [CPE][0], [CPE][1], [LFE][0] (*2)
However, when PCE comes, it assigns channels using PCE configuration as
is describled at (*1).
As you can see, only IDs are different. However, due to this
discontinuity, glitches are generated.
What this patch does:
---------------------
When assign channels on ac->che[][], use internal ID starting from zero
instead of actual ID described in PCE.
This way, channels are always assigned like (*2).
Mapping between internal ID and actual ID is resolved by
ac->tag_che_map[][].
The patch seems fine, I assume that layout_map values are within the
array boundaries (since it is what is used in the loop below) I'll just
put your explanation in the patch message and push it tonight.
lu
_______________________________________________
libav-devel mailing list
[email protected]
https://lists.libav.org/mailman/listinfo/libav-devel
_______________________________________________
libav-devel mailing list
[email protected]
https://lists.libav.org/mailman/listinfo/libav-devel
