[Release] m314dl - fast HLS/DASH downloader with built-in decryption

[mohaanymo]

I've been building my own HLS/DASH downloader and it's stable enough to put in front of people. Free, open source, and I'm the author - so weigh the benchmarks accordingly and please tell me where it falls over.

https://github.com/mohaanymo/m314dl

What it handles:

- HLS (.m3u8) and DASH (.mpd) - master/media playlists, rendition groups, byte ranges, multi-period manifests with discontinuity markers, fMP4 and TS.
- Decryption in-process and in-memory, overlapped with the download: CENC (AES-CTR), cbcs (AES-CBC pattern), cens, cbc1. No mp4decrypt or shaka-packager pass afterwards. You pass the key yourself with -key KID:KEY - m314dl does not obtain keys and has nothing to do with getting them.
- Byte-exact resume. It picks up on the exact byte mid-segment, so an interrupted download doesn't restart or come back with padding errors.
- Adaptive concurrency, AIMD between 4 and 64 in-flight requests. It backs off on its own when a server starts throwing 503s instead of you guessing a thread count.
- Live recording with -live-duration and clean Ctrl-C - you get a playable file, not a truncated one.
- Subtitles: WebVTT, TTML to SRT, stpp-in-fMP4 extraction.
- Ad-segment skipping by regex, stream selection by regex, custom headers, proxy, cookies.txt.

Speed on a 5-min 1080p HLS/TS test, same machine and connection: ~0.95s vs ~1.12s for N_m3u8DL-RE and ~1.60s for vsd. Decryption alone benchmarks ~1.4 GB/s (CTR) and ~1.05 GB/s (CBC). My box, my numbers - I'd like to see other people's.

Single static binary, no runtime deps except ffmpeg on PATH for muxing. Windows, Linux, macOS.

go build -o m314dl .

m314dl -list https://example.com/manifest.mpd
m314dl -o out.mp4 https://example.com/master.m3u8
m314dl -key KID:KEY -o out.mp4 https://example.com/manifest.mpd
m314dl -live-duration 1h -o show.mp4 https://example.com/live.m3u8

Bug reports, manifests that break it, and resume-corrupted-my-file reports all welcome - GitHub issues or reply here.

[A_n_g_e_l_a]

Good work. Another one for the armoury along with N_m3u8DL_RE and dash_mpd_cli.
It appearance is a little basic but it works and is fast.
The only slight annoyance is the order it accepts arguments in the command. If this were to be a drop-in replacement it might be a good idea to use a 'don't-care' order for them or follow the daddy-of-them all N_M3u8DL_RE's ordering.

[mohaanymo]

Good work. Another one for the armoury along with N_m3u8DL_RE and dash_mpd_cli.
It appearance is a little basic but it works and is fast.
The only slight annoyance is the order it accepts arguments in the command. If this were to be a drop-in replacement it might be a good idea to use a 'don't-care' order for them or follow the daddy-of-them all N_M3u8DL_RE's ordering.

thanks for the feedback, I will consider taking the arguments command problem and fix it in the new versions,

about the appearance, actually it meant to be this way for this reason "Automation-friendly: plain-line progress on non-TTY (no ANSI garbage in logs), real exit codes, quiet machine-readable output"

[weiLahw9]

Might want to be upfront about the AI side of the project

[mohaanymo]

Might want to be upfront about the AI side of the project

I do use AI for cleaning code and documentation

[larley]

we are drowning in AI slop

[lomero]

nice. curious to test it. thanks for sharing

[A_n_g_e_l_a]

Thanks. Neither N_m3u8DL_RE or dash_mpdcli work to download using an mpd from france.tv - the url fails in dns lookup.

The url (https://cloudingest.ftven.fr/ftv/b/70/b700192c68796/f46ded4d-5d1e-41a8-8825-78d54092f5...m/manifest.mpd) for an encrypted title works with this downloader.

So thank you for developing this.

One hiccup it picks up the subtitles but throws an error during conversion. it is a qsm stream with vtt codec.

 m314dl -key f46ded4d5d1e41a8882578d54092f512:e43d3149769ccd639ddb884fbbbae4c1 -o 'Astrid_S02E05' https://cloudingest.ftven.fr/ftv/b/70/b70
0192c68796/f46ded4d-5d1e-41a8-8825-78d54092f512-1784202207_france-domtom_DRM-SEC1.ism/manifest.mpd
selected: video=2745000.3.3 video 1920x1080 2745kbps avc1.640029 (video=2745000)
selected: audio_fre=192000.0.0 audio 192kbps mp4a.40.2 [fr] (audio_fre=192000)
selected: textstream_qsm=1000.1.0 subtitles 1kbps wvtt [qsm] (textstream_qsm=1000)
100.0% | 3425/3425 segs | 1.07GiB | 1.6MiB/s | ETA ?
warning: subtitle textstream_qsm=1000.1.0 conversion failed (ffmpeg subtitle extract failed: exit status 234
[out#0/srt @ 0xb2b85c0] Output file does not contain any stream
Error opening output file Astrid_S02E05.m314dl-subtitles-textstream_qsm_1000.1.0.srt.
Error opening output files: Invalid argument); keeping raw file Astrid_S02E05.m314dl-subtitles-textstream_qsm_1000.1.0.rawsub
done: Astrid_S02E05.mp4

I used a python downloader of my own, for the subs.

I want to emphasise to all those who sneer a someone for using AI, this worked when the other more respectable programs failed.

[mohaanymo]

Thanks. Neither N_m3u8DL_RE or dash_mpdcli work to download using an mpd from france.tv - the url fails in dns lookup.

The url (https://cloudingest.ftven.fr/ftv/b/70/b700192c68796/f46ded4d-5d1e-41a8-8825-78d54092f5...m/manifest.mpd) for an encrypted title works with this downloader.

So thank you for developing this.

One hiccup it picks up the subtitles but throws an error during conversion. it is a qsm stream with vtt codec.

 m314dl -key f46ded4d5d1e41a8882578d54092f512:e43d3149769ccd639ddb884fbbbae4c1 -o 'Astrid_S02E05' https://cloudingest.ftven.fr/ftv/b/70/b70
0192c68796/f46ded4d-5d1e-41a8-8825-78d54092f512-1784202207_france-domtom_DRM-SEC1.ism/manifest.mpd
selected: video=2745000.3.3 video 1920x1080 2745kbps avc1.640029 (video=2745000)
selected: audio_fre=192000.0.0 audio 192kbps mp4a.40.2 [fr] (audio_fre=192000)
selected: textstream_qsm=1000.1.0 subtitles 1kbps wvtt [qsm] (textstream_qsm=1000)
100.0% | 3425/3425 segs | 1.07GiB | 1.6MiB/s | ETA ?
warning: subtitle textstream_qsm=1000.1.0 conversion failed (ffmpeg subtitle extract failed: exit status 234
[out#0/srt @ 0xb2b85c0] Output file does not contain any stream
Error opening output file Astrid_S02E05.m314dl-subtitles-textstream_qsm_1000.1.0.srt.
Error opening output files: Invalid argument); keeping raw file Astrid_S02E05.m314dl-subtitles-textstream_qsm_1000.1.0.rawsub
done: Astrid_S02E05.mp4

I used a python downloader of my own, for the subs.

I want to emphasise to all those who sneer a someone for using AI, this worked when the other more respectable programs failed.

Thanks angela, could you submit this issue in the repo and I will work on it as fast as I can,
about AI, I think some people confuse using AI without understanding what it's doing (vibe coding) with using AI while having a clear understanding of what you're doing. I don't vibe coding

[weiLahw9]

Thanks. Neither N_m3u8DL_RE or dash_mpdcli work to download using an mpd from france.tv - the url fails in dns lookup.

The url (https://cloudingest.ftven.fr/ftv/b/70/b700192c68796/f46ded4d-5d1e-41a8-8825-78d54092f5...m/manifest.mpd) for an encrypted title works with this downloader.

So thank you for developing this.

One hiccup it picks up the subtitles but throws an error during conversion. it is a qsm stream with vtt codec.

 m314dl -key f46ded4d5d1e41a8882578d54092f512:e43d3149769ccd639ddb884fbbbae4c1 -o 'Astrid_S02E05' https://cloudingest.ftven.fr/ftv/b/70/b70
0192c68796/f46ded4d-5d1e-41a8-8825-78d54092f512-1784202207_france-domtom_DRM-SEC1.ism/manifest.mpd
selected: video=2745000.3.3 video 1920x1080 2745kbps avc1.640029 (video=2745000)
selected: audio_fre=192000.0.0 audio 192kbps mp4a.40.2 [fr] (audio_fre=192000)
selected: textstream_qsm=1000.1.0 subtitles 1kbps wvtt [qsm] (textstream_qsm=1000)
100.0% | 3425/3425 segs | 1.07GiB | 1.6MiB/s | ETA ?
warning: subtitle textstream_qsm=1000.1.0 conversion failed (ffmpeg subtitle extract failed: exit status 234
[out#0/srt @ 0xb2b85c0] Output file does not contain any stream
Error opening output file Astrid_S02E05.m314dl-subtitles-textstream_qsm_1000.1.0.srt.
Error opening output files: Invalid argument); keeping raw file Astrid_S02E05.m314dl-subtitles-textstream_qsm_1000.1.0.rawsub
done: Astrid_S02E05.mp4

I used a python downloader of my own, for the subs.

I want to emphasise to all those who sneer a someone for using AI, this worked when the other more respectable programs failed.

N_m3u8DL-RE 0.5.1-beta works perfectly for this stream. PEBCAK.

[danthe]

Excited to test it.

[mohaanymo]

Excited to test it.

happy to hear your feedback

[lomero]

happy to hear your feedback

My personal feedback: your app works fine, but honestly i don't find any great vantages compared to using N_m3u8DL-RE.
for me they are both the same also the only issue that i find on your app is from download it reports a % of segments like 15/900 when in reality from the folder where the command is executed the downloaded segments are much more like 250/900, so what is reported in the command window of segments number is relative wrong % compared to the real segments already downloaded.
but it's just a not relevant issue.