Gapless playback on A52 format changes?

[hupatcha]

Are there some settings in VLC that can be changed so the playback of A52 Sound is not silenced on format changes (2.0 => 5.1 or 5.1 => 2.0)?
This silencing is killing some "(famous) last sentences".
The VLC version is 2.1.2 Rincewind 64-bit on Windows 8.1 64-bit.
This is happening regardless of playing sound directly to 5.1 speakers connected analogly or using S/PDIF passthrough.
Playing the same file with Windows Media Player or the Video-APP doesn't skip sound on format change (but is downsampling the whole file to "stereo").

The log for such a file position when playing a TS-video-file:
(the change is from 2.0 to 5.1)

Code: Select all

main debug: removing module "samplerate" main debug: removing module "a52tofloat32" main debug: removing module "scaletempo" directsound debug: closing audio device main debug: removing module "float_mixer" main debug: keeping audio output main debug: reusing audio output directsound debug: Opening DirectSound Audio Output directsound debug: Windows speaker config: 5.1 and stream has 6 channels, using 6 channels directsound debug: couldn't use hardware sound buffer directsound debug: channel reordering needed main debug: output 'f32l' 48000 Hz 3F2R/LFE frame=1 samples/24 bytes main debug: looking for audio volume module matching "any": 2 candidates main debug: using audio volume module "float_mixer" main debug: input 'a52 ' 48000 Hz 3F2R/LFE frame=1536 samples/1536 bytes main debug: looking for audio filter module matching "scaletempo": 14 candidates scaletempo debug: format: 48000 rate, 6 nch, 4 bps, fl32 scaletempo debug: params: 30 stride, 0.200 overlap, 14 search scaletempo debug: 1.000 scale, 1440.000 stride_in, 1440 stride_out, 1152 standing, 288 overlap, 672 search, 2400 queue, fl32 mode main debug: using audio filter module "scaletempo" main debug: conversion: 'a52 '->'f32l' 48000 Hz->48000 Hz 3F2R/LFE->3F2R/LFE main debug: looking for audio converter module matching "any": 12 candidates main debug: no audio converter modules matched main debug: looking for audio converter module matching "any": 12 candidates main debug: using audio converter module "a52tofloat32" main debug: conversion pipeline complete main debug: conversion: 'f32l'->'f32l' 48000 Hz->48000 Hz 3F2R/LFE->3F2R/LFE main debug: conversion pipeline complete main debug: looking for audio resampler module matching "any": 3 candidates main debug: using audio resampler module "samplerate" main debug: inserting 70276 zeroes

The same part using S/PDIF passthrough:

Code: Select all

main debug: removing module "a52tospdif" directsound debug: closing audio device main debug: keeping audio output main debug: reusing audio output directsound debug: Opening DirectSound Audio Output directsound debug: using A/52 pass-through over S/PDIF main debug: output 'spdi' 48000 Hz 3F2R/LFE frame=1536 samples/6144 bytes main debug: looking for audio volume module matching "any": 2 candidates main debug: no audio volume modules matched main debug: input 'a52 ' 48000 Hz 3F2R/LFE frame=1536 samples/1536 bytes main debug: pass-through: 'a52 '->'spdi' 48000 Hz->48000 Hz 3F2R/LFE->3F2R/LFE main debug: looking for audio converter module matching "any": 12 candidates main debug: using audio converter module "a52tospdif" main debug: inserting 95188 zeroes

[Jean-Baptiste Kempf]

Yes, because it does not support format change inside the same codec, so it does deletes it to recreate it. So far, you cannot do much except giving us the sample.

[hupatcha]

How large may the sample be and where shall I put it?

[hupatcha]

Sample with 10 MiB was successfully uploaded via videolanfileuploader.

[hupatcha]

I thought that at least with s/pdif passthrough the interruption was unneccessary - the decoder in the other device (av-receiver) should handle that.

[Jean-Baptiste Kempf]

Thanks, reported.

[hupatcha]

Hmm, I'm not sure if my previous post was misleading because of bad English...
I was trying to say:
In my opinion VLC should, at least when using s/pdif passthrough,
take the A52 stream as it is, without interrupting it, and pass it to the external decoder (av-receiver).
The external decoder should then be able to cope with change in the stream by itself.

[Jean-Baptiste Kempf]

Without samples, no chance of fixing it though...

[hupatcha]

Didn't the sample arrive, that I uploaded on Mon Dec 30, 2013 12:29 pm (see Post 4)?

[hupatcha]

If the sample didn't arrive, what specific way do you prefer me to upload the sample?

[hupatcha]

It seems to be rather lonely around here...

[hupatcha]

Is there any chance for a reply?

[hupatcha]

hello?

[hupatcha]

Changes in A52 streams are so common, when playing "TS" (Transport Stream), that it would be nice, if this request wouldn't be neglected.
A sample was uploaded on Dec 30th 2013 with "videolanfileuploader" to help finding a solution.
If the sample didn't arrive nevertheless, please let me know, so I could upload it again with the method of your choice.

[hupatcha]

[hupatcha]

It's a pity that apparently there could be done nothing about that, or isn't it?
Where do you prefer me to upload that sample?
Or should I report this as a bug?