Fix: Replace 7z with ffmpeg for playable MP4 parts

[BraveVahid]

Changes Made:

• Replace 7-Zip with ffmpeg for file splitting
• Each part is now an independent, playable MP4 file
• Users no longer need special software to extract files
• Fix "File exists" error when splitting large files
• Each part is 5 minutes duration

Benefits:

• No technical knowledge required for users
• Each part plays directly on any device
• No need for file joining or extraction
• Better handling of Persian/Arabic filenames

Technical:

• Uses ffmpeg segment muxer for splitting
• Preserves original quality with stream copy
• Fallback to split command if duration detection fails
• 95MB limit for single files

[sagkhis]

It's inconvenient to split long videos into shorter 5 minutes parts. Instead add this as an option and make it the default one without replacing the 7-zip method. Thank you for your consideration

[Diana-Cl]

● ●●● Your Changes:

• Replace 7-Zip with ffmpeg for file splitting
• Each part is now an independent, playable MP4 file
• Users no longer need special software to extract files
• Fix "File exists" error when splitting large files
• Each part is 5 minutes duration

Benefits:

• No technical knowledge required for users
• Each part plays directly on any device
• No need for file joining or extraction
• Better handling of Persian/Arabic filenames

Technical:

• Uses ffmpeg segment muxer for splitting
• Preserves original quality with stream copy
• Fallback to split command if duration detection fails
• 95MB limit for single files

Hi @BraveVahid ,

First of all, thank you so much for taking the time to write this code and submit the Pull Request, Your core idea allowing users to download playable video parts without needing external extraction software is genuinely brilliant and heavily improves the UX for mobile users.

However, after reviewing the code, I decided not to merge this PR directly due to a few critical technical and UX reasons:

1. Corrupted Fallback (The split -b issue):
   In your script, if ffprobe fails to get the duration, the code falls back to split -b 90m "$FILE". This is highly problematic for video files. You cannot split an .mp4 file blindly by byte size. Doing so cuts the file without preserving the moov atom (MP4 headers), rendering the resulting parts completely corrupted and unplayable.

2. Muxing Inefficiency:
   Using a while loop to manually cut parts via ffmpeg -ss can be slow, might drop frames at the cutting points, and causes audio sync issues on longer videos.

3. User Preference (Forced Chunking):
   As pointed out by dear @sagkhis in the comments, forcing every >95MB file to be cut into 5-minute pieces can be frustrating for those downloading movies or large archives (like APKs) who prefer standard .001 archive joining. But ...
   

How we resolved this:
Inspired entirely by your PR, I have rewritten the core logic in the latest commit. Instead of replacing 7z, I added a UI Dropdown (split_method) so users can choose between standard 7z Archive or Video Chunks.
Furthermore, for the video chunking, I implemented ffmpeg -f segment -segment_time 300 which splits the video natively, safely, and instantly without corrupting the headers or needing a fallback loop.

I am closing this PR, but I want to give you full credit for sparking this feature. Thank you again for your valuable contribution and for helping make this repository better 🩶🤚🏿

[BraveVahid]

● ●●● Your Changes:

Hi @BraveVahid ,

First of all, thank you so much for taking the time to write this code and submit the Pull Request, Your core idea allowing users to download playable video parts without needing external extraction software is genuinely brilliant and heavily improves the UX for mobile users.

However, after reviewing the code, I decided not to merge this PR directly due to a few critical technical and UX reasons:

1. **Corrupted Fallback (The `split -b` issue):**
   In your script, if `ffprobe` fails to get the duration, the code falls back to `split -b 90m "$FILE"`. This is highly problematic for video files. You cannot split an `.mp4` file blindly by byte size. Doing so cuts the file without preserving the `moov atom` (MP4 headers), rendering the resulting parts completely corrupted and unplayable.

2. **Muxing Inefficiency:**
   Using a `while` loop to manually cut parts via `ffmpeg -ss` can be slow, might drop frames at the cutting points, and causes audio sync issues on longer videos.

3. **User Preference (Forced Chunking):**
   As pointed out by dear @sagkhis in the comments, forcing every >95MB file to be cut into 5-minute pieces can be frustrating for those downloading movies or large archives (like APKs) who prefer standard `.001` archive joining. But ...

How we resolved this: Inspired entirely by your PR, I have rewritten the core logic in the latest commit. Instead of replacing 7z, I added a UI Dropdown (split_method) so users can choose between standard 7z Archive or Video Chunks. Furthermore, for the video chunking, I implemented ffmpeg -f segment -segment_time 300 which splits the video natively, safely, and instantly without corrupting the headers or needing a fallback loop.

I am closing this PR, but I want to give you full credit for sparking this feature. Thank you again for your valuable contribution and for helping make this repository better 🩶🤚🏿

thank you so much for your kind and detailed review. I'm honestly just glad that I could be helpful — even if it was just an idea.