available values for transcoding

hi,

i'm new to serviio and trying to modify my transcoding profile and have a question about the available options. for the target container and target video codec, the help pages give the following information:

targetContainer - compulsory; name of container to transcode into; possible values: asf, mpeg (MPEG2PS), mpegts (MPEG2TS)
targetVCodec - optional; name of video codec to transcode into or omit this attribute to keep the video stream as it is; possible values: mpeg2video (MPEG2), wmv2 (WMV9)

does this mean that the ONLY option serviio accepts for the target container are asf, mpeg, and mpegts? Am i reading this correctly that MKV container is NOT supported?
Similar for the video codecs that the ONLY possible options are mpeg2video and wmv2 so that h264 is NOT supported?

I was going to use MKV with H264 as my default transcoding because my tv supports it, Panasonic Viera ST50, and because doing some research, these appear to be some of the better options. I'm surprised serviio doesn't support these given how they seem to be very common formats and highly regarded for their performance, so I was hoping that maybe I was misunderstanding the transocding help page. Maybe those formats listed are just examples versus a complete list.

Just as an FYI as to why I was curious, is the documentation for my tv does not say asf, mpeg, or mpegts are supported. the only containers that they have listed for video as supported are:
MP4
MKV
FLV
3GPP
PS
TS

Though i'm not sure if the TS would refer to MPEG-TS?

Thanks for any help. I"m having fun learning this, but there's definitely a lot i don't know.

[jhb50]

The purpose of transcoding is to allow formats a client does not support to be changed to a basic format that all clients support per the DLNA specs and mpeg(PS) and mpeg-ts(TS) are the commonly used containers and mpeg2Video is the commonly used codec. Transcoding to these formats is also the least demanding in terms of cpu resources and so can be performed in real time on most PC's, whereas transcoding to h264 is demanding and cannot. I believe there are also technical reasons why you cannot transcode to an mkv container.

Take a look at the various profiles to see how these have been applied for different clients.

thanks for the info, that makes sense now.

Two quick follow up question if you don't mind.

the audio options that overlap between my tv and serviio are:
mp3
aac
ac3

Would there be a recommeded audio format to default to? I"m most interested in quality and not concerned about small file size, etc.

The second question is would it generally be advisable to use something like ffmpeg to actually convert the video files I have into MKV with H264 since my tv supports it, then they wouldn't need to be transcoded? I'm just starting to build a collection, so I don't mind taking the time to convert them and I don't have any space constraints where I'm worried about size. I definitely prefer to take the extra time to have the best quality possible. Most of the information I've been able to find seems to point to H264 video being higher quality, but I can't really tell if that's only the case if the video starts off in it, or if you convert it would it still be higher quality. I"m also not positive if the serviio available options are more for widespread support and speed at the expense of a slight quality decline, etc.

Thanks again for any info.

[jhb50]

AC3 seems to be the choice probably since it supports DD 5.1. Perhaps it is also a manditory DLNA codec that every client must support.

There is no point in converting everything to h264.mkv since to can never get better quality than in the source file and probably will degrade it because you won't know the correct encoding parameters. H264 just uses less space than other codecs for similar quality. It cannot improve quality. Let the profile decide what needs to be transcoded to mpeg2video and do it on the fly.

[patters]

The reason some containers are not available for transcoding (AVI, MP4, MKV) is because owing to their design they cannot be live streamed (played by your renderer while they're being written). There's no way around this.

As for selecting an audio format to transcode to, you should probably use ac3. The FFmpeg aac encoder is reportedly not very good, libmp3lame in FFmpeg is quite a slow but good quality encoder, but the ac3 encoder is decent and extremely CPU-efficient. It even has a non-floating point version for chips like the ARM CPUs in NAS units. My 1.6GHz ARM NAS can remux mkv to m2ts while transcoding 5.1 channel ac3 in realtime, whereas it can't even encode a 2 channel mp3 in realtime.

Incidentally, if you want some help designing the profile and it's for a new device, share your work on here then it's likely to get included in future versions of Serviio. We can help you optimize it so that the transcoding is kept to a minimum.