Downloading Recordings of Broadcasts #

Stitch a long recording into a file locally #

This is a billable operation and counts as minutes of video delivered.

Long-running Live broadcasts can be replayed via HLS/DASH, but may not be available as an MP4 Download directly. However, those manifests can be used to “stitch” together the MP4 locally. Both FFMPEG and YT-DLP will do this.

Using YT-DLP for Simple Downloads #

YT-DLP is more user-friendly, has built in Stream support, and can parallelize the operation to make it much faster.

yt-dlp -N 40 https://customer-<CODE>.cloudflarestream.com/<VIDEO_ID>/watch

The -N option enables parallel segment downloads to process faster.

Using FFMPEG for Advanced Cases #

FFMPEG can do this too, with options to modify or re-encode the video in the process. On the other hand, it does not fetch segments in parallel so these operations can be much slower.

ffmpeg -i "https://customer-<CODE>.cloudflarestream.com/<VIDEO_ID>/manifest/video.m3u8" -acodec copy -vcodec copy output.mp4

To download only part of a video, provide a start time and duration. This is a workaround to achieve long clips from live recordings. (Just need a short clip?)

Download ten minutes from a given manifest, starting thirty minutes in:

# Fast - Stream Copy from DASH Manifest
ffmpeg -ss 00:30:00 -t 00:10:00 -i "https://customer-<CODE>.cloudflarestream.com/<VIDEO_ID>/manifest/video.mpd" -c copy output.mp4

# Precise - Transcoding from HLS Manifest
ffmpeg -i "https://customer-<CODE>.cloudflarestream.com/<VIDEO_ID>/manifest/video.m3u8" -ss 00:30:00 -t 00:10:00 -acodec aac -vcodec libx264 output.mp4

Start time: -ss HH:MM:SS specifies how far to seek into the manifest before recording
Duration: -t HH:MM:SS specifies how long the output should be

There are some gotchas when Seeking with FFMPEG. Specifying the -ss seek before the input performs a much faster input seek.

FFMPEG seems to drop either the audio or video track when seeking and doing a stream copy from the middle of an HLS manifest. Thus the two options:

Stream copy and input seek from the DASH manifest is much faster, but if the clip occurs in the middle of a GOP/keyframe interval, the initial frames could be corrupted until the next keyframe.
Output seek and transcoding from the HLS manifest is much slower, but ensures audio and video start simultaneously in a good state.

To download only the audio from a video, copy the audio but discard the video:

ffmpeg.exe -i "https://customer-CODE.cloudflarestream.com/VIDEO_ID/manifest/video.m3u8" -vn -acodec copy output.m4a

This will copy the audio as-is and skip the video (-vn). This isn’t appropriate for an HLS manifest with multiple audio tracks or if the audio and video lengths are different.