tdh-twitch-utils 1.2

Record, concatenate and synchronize Twitch live streams

Python utils for Twitch

pip3 install tdh-twitch-utils

This module consists of three different scripts:

concat

This script uses MPEG-TS timestamps to concatenate multiple video segments into a single file without re-encoding. It is most useful for assembling partial stream recordings in case of interruption or error during stream download. Overlapping parts will be removed precisely with ffmpeg's concat demuxer.

Example

# download two overlapping segments (60 seconds each)
VOD="YOUR VOD ID"
streamlink -o 1.ts --hls-duration 60 "twitch.tv/videos/$VOD" best
streamlink -o 2.ts --hls-start-offset 30 --hls-duration 60 "twitch.tv/videos/$VOD" best

# concatenate two segments into one video
twitch_utils concat 1.ts 2.ts -o result.mp4

# create one segment
twitch_utils concat 1.ts 2.ts -o result.ts

# pipe concatenated MPEG-TS stream to other applications
twitch_utils concat 1.ts 2.ts -o - | ffmpeg -i - -c copy result.mp4

record

This script can be used to record live streams without waiting for them to end. It starts to record live stream immediately, then downloads VOD and concatenates them into full stream recording.

Obviously, this script requires channel to have public VODs and streams.

Algorithm:

1. Check if channel is live and VOD for current stream already exists;
2. Get VOD ID from Twitch API (uses part of Twitch-Chat-Downloader library);
3. Start downloading live stream into file VOD.end.ts;
4. Wait 10 minutes and start downloading VOD into file VOD.start.ts;
5. Wait for both downloads to finish;
6. Concatenate two parts via concat script (see above).

Bandwidth limiting is implemented by piping output of streamlink through pv utility, thus you will need to install this program to use -b flag.

Example

# Record live stream of channel 'blackufa' using 2 threads and
# limiting bandwidth to 2 MiB/s

twitch_utils record blackufa -j 2 -b 2M 

offset

This script performs cross-correlation of two audio files to find offset between them. First argument is cropped and used as template. Second argument can have any duration -- it will be divided into separate chunks to reduce memory usage (otherwise it wouldn't be possible to use exceptionally big files). Both arguments can be videos or audio files -- audio track will be extracted and converted. You can even use HTTP links if ffprobe is able to correctly determine second argument's duration.

Example

# Cut small segment from big video file (offset: 123 seconds)
ffmpeg -ss 123 -i YOUR_FILE.mp4 -t 60 -c copy template.mp4

# Find offset of template.mp4 within YOUR_FILE.mp4
twitch_utils offset template.mp4 YOUR_FILE.mp4
# ... returns 122.99997732426303

# Same command, but result will be rounded to nearest integer
twitch_utils offset template.mp4 YOUR_FILE.mp4 --round
# ... returns 123