Return to Answer

Assuming you have no audio problems, be assured you have audio in this file, and also what type of audio you have, reading sources with ffmpeg -i file.mkv or with MediaInfosoftware.

Then,

Try with ffmpeg:

ffmpeg -i filename.mkv -c:v copy -c:a aac output.mp4

To see the results and I'm assuming here you're not trying to play it on internet.

Also try with other players if it's Linux and Media Player Classic if it's Windows.

There's a reason why I've mentioned ffmpeg.

UPDATE: Try ˋffmpegˋ from the official website and that haven't been compiled from any other sources yet.

As I've seen you're using a compiled version from KMPlayer, and you're not supossed to use that.

Some notices:

• you cannot use .h264/video and opus/audio together in a .mp4 container since it isn't compatible, it needs to be inside .mkv container. The reason why I've mentioned to convert it to aac/audio to solve this issue.

• As well avoid the mistake, if any, to download specific audio/video format for then to interrupt and continue from another video/audio format since it will break the file anyways

Assuming you have no audio problems, be assured you have audio in this file, and also what type of audio you have, reading sources with ffmpeg -i file.mkv or with MediaInfosoftware.

Then,

Try with ffmpeg:

ffmpeg -i filename.mkv -c:v copy -c:a aac output.mp4

To see the results and I'm assuming here you're not trying to play it on internet.

Also try with other players if it's Linux and Media Player Classic if it's Windows.

There's a reason why I've mentioned ffmpeg.

UPDATE: Try ˋffmpegˋ from the official website and that haven't been compiled from any other sources yet.

As I've seen you're using a compiled version from KMPlayer, and you're not supossed to use that.

Some notices:

• you cannot use .h264/video and opus/audio together in a .mp4 container since it isn't compatible, it needs to be inside .mkv container. The reason why I've mentioned to convert it to aac/audio to solve this issue.

• As well avoid the mistake, if any, to download specific audio/video size format like 720p to then interrupt and continue it from another size video/audio format like 1080p to the same container as it will break the file anyways

Assuming you have no audio problems, be assured you have audio in this file, and also what type of audio you have, reading sources with ffmpeg -i file.mkv or with MediaInfosoftware.

Then,

Try with ffmpeg:

ffmpeg -i filename.mkv -c:v copy -c:a aac output.mp4

To see the results and I'm assuming here you're not trying to play it on internet.

Also try with other players if it's Linux and Media Player Classic if it's Windows.

There's a reason why I've mentioned ffmpeg.

UPDATE: Try ˋffmpegˋ from the official website and that haven't been compiled from any other sources.

As I've seen you're using a compiled version from KMPlayer, and you're not supossed to use that.

Notice as well you cannot use .h264/video and opus/audio together in a .mp4 container since it isn't compatible, it needs to be inside .mkv container. The reason why I've mentioned to convert it to aac/audio.

If still not working, try to download YouTube videos with

youtube-dl -iwc -f 247+251 - id-video-url

into a new folder.

use -F for more options

The most important part here is that you don't download specific audio/video format for then to interrupt and continue download it from another video/audio format since will break the file, and to avoid future mistakes.

Assuming you have no audio problems, be assured you have audio in this file, and also what type of audio you have, reading sources with ffmpeg -i file.mkv or with MediaInfosoftware.

Then,

Try with ffmpeg:

ffmpeg -i filename.mkv -c:v copy -c:a aac output.mp4

To see the results and I'm assuming here you're not trying to play it on internet.

Also try with other players if it's Linux and Media Player Classic if it's Windows.

There's a reason why I've mentioned ffmpeg.

UPDATE: Try ˋffmpegˋ from the official website and that haven't been compiled from any other sources yet.

As I've seen you're using a compiled version from KMPlayer, and you're not supossed to use that.

Some notices:

• you cannot use .h264/video and opus/audio together in a .mp4 container since it isn't compatible, it needs to be inside .mkv container. The reason why I've mentioned to convert it to aac/audio to solve this issue.

• As well avoid the mistake, if any, to download specific audio/video format for then to interrupt and continue from another video/audio format since it will break the file anyways

Assuming you have no audio problems, be assured you have audio in this file, and also what type of audio you have, reading sources with ffmpeg -i file.mkv or with MediaInfosoftware.

Then,

Try with ffmpeg:

ffmpeg -i filename.mkv -c:v copy -c:a aac output.mp4

To see the results and I'm assuming here you're not trying to play it on internet.

Also try with other players if it's Linux and Media Player Classic if it's Windows.

There's a reason why I've mentioned ffmpeg.

UPDATE: Try ˋffmpegˋ from the official website and that haven't been compiled from any other sources.

As I've seen you're using a compiled version from KMPlayer, and you're not supossed to use that.

Notice as well you cannot use .h264/video and opus/audio together in a .mp4 container since it isn't compatible, it needs to be inside .mkv container. The reason why I've mentioned to convert it to aac/audio.

Try to download YouTube videos with

youtube-dl -iwc -f 247+251 - id-video-url

into a new folder.

use -F for more options

The most important part here is that you don't download specific audio/video format for then to interrupt and continue download it from another video/audio format since will break the file, and to avoid future mistakes.

Assuming you have no audio problems, be assured you have audio in this file, and also what type of audio you have, reading sources with ffmpeg -i file.mkv or with MediaInfosoftware.

Then,

Try with ffmpeg:

ffmpeg -i filename.mkv -c:v copy -c:a aac output.mp4

To see the results and I'm assuming here you're not trying to play it on internet.

Also try with other players if it's Linux and Media Player Classic if it's Windows.

There's a reason why I've mentioned ffmpeg.

UPDATE: Try ˋffmpegˋ from the official website and that haven't been compiled from any other sources.

As I've seen you're using a compiled version from KMPlayer, and you're not supossed to use that.

Notice as well you cannot use .h264/video and opus/audio together in a .mp4 container since it isn't compatible, it needs to be inside .mkv container. The reason why I've mentioned to convert it to aac/audio.

If still not working, try to download YouTube videos with

youtube-dl -iwc -f 247+251 - id-video-url

into a new folder.

use -F for more options

The most important part here is that you don't download specific audio/video format for then to interrupt and continue download it from another video/audio format since will break the file, and to avoid future mistakes.