Features, settings & updates

[Amelia3]

Thanks

I'm going to give it a try -  only my time and a good learning experience

[AvsGunnar]

Here is the official ffmpeg docs. https://ffmpeg.org/ffmpeg.html

Here is the official ffmpeg downloads. https://ffmpeg.org/

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Once you get setup, you may just want to try a simple remux and see if that fixes the file. (always make a backup of file before running through ffmpeg until you get comfortable with it). 

ffmpeg -i b.mp4 -c:v copy -c:a copy b.mkv

[I just rename my files to simple letters when using ffmpeg commands, like "b" in above example. (others may just use the word "movie"),  This keeps the commands simple.  Once I am done, I will then just rename "b" to the desired final filename.

The above command will simply change your mp4 to mkv with corresponding audio.  This is one of my most used commands since it will also me to add subtitles to different formats (with other ffmpeg commands) and then finalize my output without that long encoding process. It will automatically use the correct audio codec with the video codec unless specified otherwise.

Here are a couple simple tutorial pages with the most common commands you will likely need when using ffmpeg.

https://shotstack.io/learn/how-to-use-ffmpeg/

https://ostechnix.com/20-ffmpeg-commands-beginners/

https://gist.github.com/steven2358/ba153c642fe2bb1e47485962df07c730 (command cheat sheet)

[Amelia3]

Again - thank you so much for the info.   

Stay tuned for my success!

[Amelia3]

Hi

I tried using ffmpeg changing MP4 to MKV and no change in audio

The actual CODEC changed as follows

FROM
MP4 Codec: A/52 B Audio (aka E-AC3) (ec-3)

TO
MKV Codec: A/52 B Audio (aka E-AC3) (eac-3)

The ROKU is connected to a 2014 Sony 55" Bravia -  using TV internal speakers only - no external sound device - so runs in 'stereo' mode (eg 2 speakers)

From ROKUs supported formats for Audio and Subtitles

AAC or MP3 with MKV
OR
AAC or MP3 with MP4

OR

DTS  with MKV or MP4

If there are more combinations than these to try, please advise  - each test for a fixed output requires driving to the neighbor who has the problem, as I can't find any way to recreate where I live --  I guess driving beats getting on an airplane!

Again THANKS!

[atc98092]

The fact the audio is EAC-3 is the issue, and it has nothing to do with the Roku. EAC-3 is Dolby Digital Plus (DD+), and most TVs cannot process that audio codec. So you need to convert the audio to AC3 or AAC. 

Roku devices support EAC-3, but whatever is receiving the audio has to be able to play it. If you were using an AVR or soundbar with DD+ support your media would play fine, as the sound would be processed without being sent to the TV. Since your TV is as old as it is, it likely does not support eARC, so would not be able to send DD+ back to an AVR from a device connected directly to the TV. ARC (the original version of the Audio Return Channel) does not have the bandwidth to send DD+ (or higher quality) back to an AVR/soundbar.

[AvsGunnar]

@Amelia3 

Ok, one may be handled with a phone call to the neighbor.  Now that you have the EAC3 audio codec in the MKV format, you may be able to toggle the Volume Mode as described earlier and the video should hopefully play with sound.

1. Play the MKV file.

2. While video is playing, press the asterisk (*) button on Roku remote.

3. Select Off or choose another Mode. (should now hopefully see circle and audio begins).

4. Change Volume Mode to preferred level and video will continue to play with audio until the next time you select this video file. (or any other file suffering this issue.  Just have to toggle each time).

**I just made a MP4 with a AC3 audio codec, and the Toggle Method did not work, so seems to only work when the container is MKV on the 4660. (like you have now).

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Second Method (convert EAC3 to AAC) - can use either MP4 or MKV 

Just run this ffmpeg command. (using the MKV file you have now,.  For command purposes, I will assume the original file is called roku.mkv and the new file that will be created is newroku.mkv).

ffmpeg -i roku.mkv -vcodec copy -acodec aac -strict -2 newroku.mkv

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After creating newroku.mkv, and after testing it (it should now work using AAC instead of EAC3), if you want your file to be in mp4 format, just use the remux command.

ffmpeg -i newroku.mkv -c:v copy -c:a copy newroku.mp4

This just changes the container and you should still be good to go.

Feel free to post back if still having issues.

Edited to add... If you do the second method, you won't need to do the volume toggling on the 4660 any longer on the mkv files).  Because I have various files on different drives giving me this issue on my 4660, but not my newer Ultra devices, I have just been using the Volume toggle method as necessary.   But I mostly convert everything into mkv. (kind of why I didn't notice the toggle does not seem to appear to work on mp4 files).

[Amelia3]

Thx

I did try volume toggle  w/ MKV  --no change.

I confirmed another video (that didn't have subtitles) with AAC works  -- so changing to use that codec from EAC3  -- will save as MKV per the end of your response.

MPEG-4 Video (mp4v)

MPEG AAC Audio (mp4a)

telephone support  -- isn't easy with customer, not technically/electronically inclined

[Amelia3]

Thx  -- for AC3 definition  -- changing to AAC  -- so between you and AVSGunner's help I should be working

ALL WORKS  -- thank you both again

[Amelia3]

I'm back - and this is more of an ffmpeg question, but I thought I'd ask

I got the following batch job working as I have a lot of mp4s to convert

                 for %f in (*.mp4) do ffmpeg -i "%f" -c:a aac "%~nf_new.mkv"

However, it is very slow - I get frame=84707 fps= 44 q=28.0 bitrate=1069.6kbits/s speed=1.75x

I have tried -speed 8,    -preset ultrafast, and others - though I get syntax errors on anything I try, from searches I have gotten hits on.

I am running on a windows 10

Use a faster x264 encoding preset. A preset is a set of options that gives a speed vs compression efficiency tradeoff. Current presets in descending order of speed are: ultrafast, superfast, veryfast, faster, fast, medium, slow, slower, veryslow, placebo.

Thanks if any ideas -- 

[AvsGunnar]

@Amelia3 

SuperUser is a pretty good site to explore for ffmpeg (this is the unofficial forum for ffmpeg as ffmpeg does not have its own but refers users there).

https://superuser.com/questions/tagged/ffmpeg

https://ffmpeg.org/contact.html#Forums

StackOverFlow is another good site.  A lot of coders/developers over there on that site as well that know the ins/outs of ffmpeg.  https://stackoverflow.com/search?q=ffmpeg&s=cc7244df-1361-4b02-a82f-de9276accca8

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As explained in one of the SuperUser threads (users are always asking how to speed up processing time) , https://superuser.com/questions/1859010/how-can-i-speed-up-the-processing-time-when-using-ffmpeg, you really can't speed it up w/o losing quality. (only way is to change the video/audio quality so processing not so long, but you can't just "speed up the time" needed for the operation.  Faster computers, or course, will help.  Using multiple computers is another method.

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The only batch commands I use with ffmpeg are when I concat (merge video files into longer videos) but for everything else I just use the single operation commands so I can see any errors generated.  In some cases, I will start two seperate operations in two different terminals on same laptop, but not typically.

Batch files aren't bad when all the videos are exactly the same, but when you have different settings in different videos, not uncommon to get errors or undesired results.