Downloaded video file unplayable.

[DhanrajHira]

The download completes without issues but the resultant .mp4 file is unplayable.

My guess

Skiping the first chunk (intro) causes this issue.

[DhanrajHira]

Looks like my guess was correct, I commented out the code that was supposed to remove the intro chunk from the file and the video is playable now. Either the way we check for the first chunk removes some required data or the first chunk contains some meta data required by the player.

[notmarek]

Huh the complete opposite is the case for me

[DhanrajHira]

Do you mean that including the intro chunk breaks your video file?

[notmarek]

That's correct

[DhanrajHira]

Well this is wierd, if I remember correctly, the M3U8 object had an is_independent_chunks property. Maybe different streams are encoded differently. We'll have to look into this, can you tell me the anime ID and episode number of any other anime that you were able to download while removing the intro?

[notmarek]

I was able to download everything i tried, for example you can try the example in readme

[notmarek]

Also i just tried downloading the anime you previously mentioned in the other issue and its unplayable with the intro

[DhanrajHira]

Okay I'll try the one included in the README file. Just to make sure, you downloaded the ld quality right?

[notmarek]

I downloaded all the qualities when i was testing, but i mostly download fullhd

[notmarek]

Also when i try to use ffmpeg with the intro chunk it says [png_pipe @ 00000147ba5acf80] Stream #0: not enough frames to estimate rate; consider increasing probesize
and then video:198927kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.000411% basically saying there's no audio

[DhanrajHira]

The intro chunk is a gif so that's probably why there is no audio.

[DhanrajHira]

Ignore my previous comment I don't know what I was thinking.

[notmarek]

aaf71c7

[DhanrajHira]

I have tried both the default windows player and VLC.

Here's what I found:

Somali to Mori no Kamisama (2069)

With intro:

VLC: Broken
Default Windows Player: Working

Without intro:

VLC: Working
Default Windows Player: Working

God of High School (2506)

With intro:

VLC: Broken (10 seconds of nothing and that too only audio)
Default Windows Player: Working

Without intro:

VLC: Working
Default Windows Player: Broken

[DhanrajHira]

Inference

Looks like VLC works consistently when there is no intro, while the default player works consistently when the intro chunk is present. Further testing is required to make any solid claims.

We can also look into always skipping the intro and then joining the chunks using ffmpeg, maybe that will make it work consistently with the default player. What do you think?

[DhanrajHira]

Yup, looks like I was right, using ffmpeg to convert chunks into .mp4 makes it so that the file works with the default player even if the intro is skipped. I tested this on the "God of High School" episode. As you can see above, without ffmpeg it didn't work with the default player if the intro chunk was skipped but by using ffmpeg it works flawlessly. Furthermore, the file size seems to be noticeably smaller.

[DhanrajHira]

The current implementation of the download functionality seems satisfactory to me. I will make a note reminding us to talk about this quirk in the documentation. I think the issue can be closed now, I am leaving the issue open, if you feel satisfied, Kindly close the issue,

[notmarek]

I will add this info to the README and then close this issue

[notmarek]

68f670f