dts files in real time, with stereo downmixing) some patching may be required, as recent ffmpeg from current CVS snapshot is unable to downmix 5.1 DTS audio to stereo on arm v6 platform 30% CPU utilisation while decoding and playing. ffmpeg DTS decoding implementation seems to be the most efficient (ca. To test software DTS decoding possibilities I compiled libdca/dcadec, ffmpeg and mplayer for ARM v6 CPU with VFP optimizations turned on, and here are preliminary results: Stereo and 5.1 pcm/wav files are playable with aplay (from debian lenny armel alsa-utils package), and SPDIF passthrough for AC3 & DTS files seems to work well with mplayer. But basically it works, except for the mixer (very limited settings available for analog audio it's a known limitation for this device on older kernels and alsa versions). Compiling kernel modules for USB audio is the easy part setting up & configuring ALSA not that easy one. As it turned out, after some fiddling, it also works while connected to the TV. Recently I got my hands on external USB sound card (Creative Sound Blaster Live! 24-bit External USB). Or uldAvfd_InterfacerSkipUnknownEsData() ? I want to try some things. If someone would like to participate, I could attach my sources logging PES headers, packets etc.ĭo you think, may it be possible to capture / dump audio streams from (e.g) uldAvfd_InterfacerSkipUnknownData() I looked into samdrv.ko (the better part of it is apparently related to audio decoding, mostly "AIDA" engine microcodes for various audio formats), and - oh boy- samsung sound processing is just FUBARĭoes anyone know an easy method for adjusting kernel-level dubugging loglevels temporarilly by some exeDSP function call? It is possible to switch debugging on/off for various subsystems in debug menu, but those settings are remebred in NVRAM between reboots, which may be a little dangerous sometimes (as I learned in hard way). I guess it is still not sure if samsung SPDIF is able to transmit DTS stream hardware-wise, am I right? There are many low-level functions for SPDIF Tx setup in samdrv.ko, and some related options in debug menu, but for me they are not very entlighting. Is it done by some function in samdrv.ko module, or maybe directly in hardware audio engine? It looks like TV is encapsulating AC3 packets with PES headers for future processing (in uldAvfd_InterfacerAudioAc3TransferBufDataWithPESHdr ?) but I can't find where are those headers striped before sending packets to SPDIF. Hmm, I'm not sure I fully understand all this. The problem seems to be only in PES header, which is created by exeDSP and is not created correctly for DTS stream - it seems the problem is related to the PTS field in PES header. Doodlecz wrote:Just short info about (almost no) progress.ĭTS audio stream read from MKV is imo correct when DTS stream is processed as AC3 (packets with DTS sync word on the beginning and correct length are read)
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |