EliteGroup 3 Posted March 3 Share Posted March 3 Hi Guys, Isn't it possible to transcode just the audio track in a stream? (Like with H264) I try on emby but it doesn't work. will it work in the future? For example, if an AV1 file has an audio track with DTS and the device does not support DTS, then H264 will only transcode the audio track. <- AWESOME This doesn't work with HEVC, that's why I hate HEVC and was hoping it works on AV1... But apparently if the audio codec is not supported by the client, AV1 is transcoded to H264, is there no audio coding alone with AV1 either? That would be really bad if you have a lot of DTS and 1 or 2 people with LG TV without DTS license or Browser play Another question: Would you rather choose MKV or MP4 for AV1? I heard MP4 is better for remote streaming. Another question: why is AV1 to AV1 (or HEVC to HEVC) transcoding not supported if the audio format doesn't fit or you want a lower video bitrate? It is always XY to H264 which means a high loss of quality and bandwidth. AV1 / HEVC encode + decode is possible to reduce the bit rate or correct the audio track? Link to comment Share on other sites More sharing options...
Luke 37095 Posted March 4 Share Posted March 4 Hi there, let's look at an example. Please attach the information requested in how to report a media playback issue. Thanks! Link to comment Share on other sites More sharing options...
EliteGroup 3 Posted March 4 Author Share Posted March 4 2 hours ago, Luke said: Hi there, let's look at an example. Please attach the information requested in how to report a media playback issue. Thanks! Hi @Luke I don't have any playback issue. I would like to know if it is possible on AV1 to transcode only the audio track if this is not supported. Example: AV1 + DTS sound If the client does not support DTS the video will be transcoded to h264 + audio to aac,mp3,... Transcoding only “audio” stream not possible on AV1 codec? Link to comment Share on other sites More sharing options...
Luke 37095 Posted March 5 Share Posted March 5 The answer is always that it depends, which is why I asked for a specific example. So without that, I would say usually yes, but not necessarily always. Link to comment Share on other sites More sharing options...
EliteGroup 3 Posted March 5 Author Share Posted March 5 (edited) 5 hours ago, Luke said: The answer is always that it depends, which is why I asked for a specific example. So without that, I would say usually yes, but not necessarily always. I'll make an example for you. Example 1: MP4 + AV1 + AAC Sound its direct play, no transcoding video/audio Example 2 (see attached file) : MP4 + AV1 + EAC3 Sound Emby dashboard says: "audio not compatible" I'm playing this on firefox. The same file with AAC audio stream is direct play. Just like in this example as well as with LG TV or other devices, if AV1 is played with a matching audio track, it will be played directly. If the audio track is not suitable for the device then the video codec will be transcoded from AV1 to H264 for stream. Example 3 (see attached file) : MKV + AV1 + EAC3 Sound Emby dashboard says: "container not compatible" I know under Firefox only MP4+AV1+AAC works. Google Chome also has support for MKV, Firefox does not. Could it be the problem with the nVidia Quadro P2000 which doesn't support AV1? I would like to buy an Intel ARC A380 that supports AV1 encode/decode, but only after my tests are completed. But could it be that AV1 -> H264 transcodes just because the audio track doesn't fit? MKV_ffmpeg-remux-f82db6b1-48e2-4466-8ef7-0f4ea7d2cf8f_1.txt MKV_ffmpeg-transcode-7c5f8236-d618-4116-9dbd-038774bf7701_1.txt MP4_ffmpeg-remux-79eb55b9-7897-4b8f-adda-4eb528502b96_1.txt MP4_ffmpeg-transcode-16bdbe86-dfe9-4993-836c-b6ea57ebf90c_1.txt Edited March 5 by EliteGroup Link to comment Share on other sites More sharing options...
EliteGroup 3 Posted March 10 Author Share Posted March 10 @LukeNo idea? I would like to transcode my library to AV1. But I need to know whether the audio track can be transcoded alone when streaming. otherwise I have to transcode DTS/EAC3... into AAC and keep the original track. This would not be necessary if the audio track was transcoded without video. (With H264 every audio track can be transcoded alone without video encoding) Best regards Link to comment Share on other sites More sharing options...
RanmaCanada 345 Posted March 10 Share Posted March 10 Speaking as an encoder, AV1 is still in its infancy for support so this will probably take a while. It also doesn't help that the documentation is rather lacking and that there is so much fragmentation. It's highly possible that Emby is throwing the entire stream under the bus to take the easiest/safest route out. For example, AC3 in an mp4 container is not really standard, so they may be taking the safest approach to make everything "standard", ie video and audio codec. I know it's not the answer someone wants to read, but that is a possiblility from a playback standpoint. It's "always best" to bring things to the safest possible standard (ie lowest common denomintator) when something isn't supported or as expected. I would say give the devs more time to understand the handling of AV1 and it's dumbness. We will more than likely see the same thing happen with VVC and AV2. 1 Link to comment Share on other sites More sharing options...
EliteGroup 3 Posted March 10 Author Share Posted March 10 (edited) @RanmaCanada Thanks for your answer. I couldn't find an answer in Google, so I'm asking. One possibility would be to encode each audio track to AAC and keep the original audio track (if it is DTS). This works with HEVC, with HEVC it is 100% that the audio track alone cannot be converted when streaming. The device/Emby automatically selects supported audio track. It would be good to know whether I could save the double soundtrack (DTS + AAC). Unfortunately, no one can say that yet. I've already found out a lot of information: Firefox only supports AV1 MP4+AAC, AV1 MKV only supports MP3. Chrome supports AV1 MP4+MKV with AAC This may change with updates in the future... LG TV does not officially support AV1, but it can be played (Software Encode). Emby Client forces AV1 transcoding to H264 on LG TV. In Emby, “transcoding” must be disabled for the user. Then play AV1 directly on the LG TV. Emby Bug maybe?! All FireTV Sticks play AV1 without any problems, even if officially only the FireTV 4k Max 2nd Gen supports the AV1 hardware codec. Emby can be played directly here, but not yet on LG TV. nVidia Shield does not support AV1 neither hardware nor software. Both cannot be played. It's a shame my Shield Pro cost a lot... Tomorrow I will test Xiaomi 4k Box Edited March 10 by EliteGroup Link to comment Share on other sites More sharing options...
RanmaCanada 345 Posted March 10 Share Posted March 10 @EliteGroupI can speak from experience that the Gen 3 Amazon Firecube 100% supports AV1, as does the Firestick 4k MAX line (though the Firesticks have issues with hybrid DV/HDR10+ files, Firecube does not). I made my comment as even on Doom9, where some of the devs of AV1 hang out, when we ask them for instructions on how to encode things and WHY we should use such switches, we are told "use this, and STFU" with no explanations on what those switches do, why they do it etc. It's really frustrating. I would like to do more AV1 encoding myself, but some don't respect threading so it runs single threaded, others if you use too much threading it drops the quality, to grain synthesis not being supported on some devices, etc. 1 Link to comment Share on other sites More sharing options...
Luke 37095 Posted March 15 Share Posted March 15 @EliteGrouphas this answered your questions? Link to comment Share on other sites More sharing options...
EliteGroup 3 Posted March 15 Author Share Posted March 15 Hey @Lukethanks for your question, yes and no... Downmixing audio while streaming AV1 directly in Emby has not yet been answered. Maybe have to wait until we know more about this codec. Thank you Link to comment Share on other sites More sharing options...
Luke 37095 Posted March 16 Share Posted March 16 23 hours ago, EliteGroup said: Hey @Lukethanks for your question, yes and no... Downmixing audio while streaming AV1 directly in Emby has not yet been answered. Some Emby apps can do this now. 1 Link to comment Share on other sites More sharing options...
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