Download YouTube Videos in ProRes or DNxHR

What does ProRes or DNxHR export in B-ROLL do?#

B-ROLL downloads a YouTube video, then converts it automatically to a ProRes or DNxHR .mov that keeps the source resolution and frame rate. You choose ProRes or DNx in the Format menu, and B-ROLL chooses the tier for each video.

The export happens in two steps. First, yt-dlp merges the best video and audio streams within your Quality cap into an MKV master. Then ffmpeg converts that master into a .mov with the same name and deletes the MKV once the conversion succeeds.

Conversions have their own queue and run one file at a time. The next download starts while the previous file converts, so on a playlist the downloading and the converting overlap. Each video in a playlist gets its own tier.

The conversion exists because of what YouTube delivers. As of September 2026, yt-dlp’s default pick for an MP4 or MKV download is usually AV1 or VP9 video with Opus audio: long-GOP codecs that are heavy to decode when you scrub. ProRes and DNxHR compress every frame on its own, so scrubbing and reverse playback stay light.

Ema Zamboni, the video editor who made B-ROLL, built this step for a real timeline problem. In DaVinci Resolve Studio on Windows 11, 4K60 AV1 footage downloaded from YouTube was heavy to play back, and AV1 or VP9 downloads crashed Resolve at times.

A transcode keeps the picture YouTube’s encode left; it adds no detail. The best format to download YouTube videos for editing weighs that trade against MP4, and the other export options are on B-ROLL features for video editors.

Which ProRes or DNxHR tier does B-ROLL pick?#

B-ROLL picks the lightest tier whose data rate is at least 10 times the source bitrate, after scaling each tier to the video’s resolution and frame rate. DNxHR HQX is used only when the source is 10-bit, and then always; B-ROLL’s ProRes is always 10-bit 4:2:2.

The scale factor is (width x height x fps) / (1920 x 1080 x 29.97), so a 2160p30 video has a scale of 4.004. ffmpeg measures the source bitrate on the MKV master. When no tier reaches 10 times the source, B-ROLL uses HQ; when the bitrate cannot be measured, it uses the lightest tier.

The 10x factor comes from a comment in B-ROLL’s code: an intra-frame codec is visually transparent to a source at 10 times its bitrate, so a heavier tier only fills the disk. The worked examples and the reasoning are in how B-ROLL picks a ProRes or DNxHR tier automatically.

The table shows, for 1080p30 and 2160p30 videos, the highest source bitrate for which B-ROLL still picks each tier, computed from B-ROLL’s internal reference rates (the DNxHR values are not Avid’s published figures).

A 1080p30 upload at 8 Mbps therefore becomes DNxHR SQ or ProRes 422 LT. Doubling the frame rate doubles every limit: at 2160p60 (scale 8.008), DNxHR SQ covers sources up to 99.3 Mbps (124 x 8.008 / 10) and ProRes 422 LT up to 81.7 Mbps (102 x 8.008 / 10).

B-ROLL’s ProRes reference rates equal the target data rates in Apple’s ProRes overview: 45, 102, 147 and 220 Mbps at 1920 x 1080 and 29.97 fps. Its DNxHR rates are its own: Avid’s bandwidth table lists DNxHR HQ at 25.99 MB/s at that size, which is 207.92 Mbps (25.99 x 8). The vendor ladders are in ProRes Proxy vs LT vs 422 vs HQ and DNxHR LB vs SQ vs HQ vs HQX.

Clips follow the same rule, measured on the clip’s own master. Because clip downloads prefer YouTube’s HLS streams, a clip and a full download of the same video can end up on different tiers.

How long does the ProRes or DNxHR conversion take?#

B-ROLL shows no time estimate for a conversion: the card reads to convert, then converting… with a percentage. The length depends on your processor, the video’s duration and its pixel rate, because the conversion uses every CPU core.

Pixel rate is the part you can predict. A 2160p60 video carries 8.008 times the pixels per second of 1080p 29.97 (3840 x 2160 x 60 divided by 1920 x 1080 x 29.97), so the same PC needs longer to encode each minute of it. The Format menu marks ProRes and DNx with the hint “slow”.

Your machine stays busy while a file converts, so start long playlists when you are not editing on the same PC. You can stop a conversion from its card; the log then reads “Conversion stopped.”

The output also needs disk space. ProRes and DNxHR file size per minute gives the sizes at 1080p and 4K, and the B-ROLL log prints the chosen tier with an estimated size, for example for a DNx export:

🎞 DNx tier auto-picked: SQ  (source ~8.0 Mbps -> output ~124 Mbps, ~1.2 GB)

When the progress bar crawls before the card ever reaches “to convert”, the delay is in the download itself, not the conversion. YouTube download slow or throttled covers those causes and fixes.

What does a B-ROLL ProRes or DNxHR .mov contain?#

A B-ROLL .mov holds one video track in ProRes or DNxHR and one audio track in uncompressed 16-bit PCM, at the source’s own resolution and frame rate. B-ROLL passes no scaling or frame rate option to ffmpeg.

The table lists what each export writes into the file.

ProRes files from B-ROLL are ProRes-compatible files made with ffmpeg’s encoders, not with Apple’s own encoder. The FFmpeg codecs documentation covers the prores_aw and prores_ks encoders and the vendor option. When B-ROLL falls back to prores_ks, it sets the vendor ID apl0, which labels the stream as if Apple’s encoder had made it.

DNxHR files use ffmpeg’s dnxhd encoder with DNxHR profiles only, so B-ROLL never writes DNxHD. If the HQX encode fails on a 10-bit source, B-ROLL falls back to DNxHR SQ at 8-bit. Clips keep their time range in the name, in minutes and seconds only, for example Interview [02-10 to 02-38].mov.

ProRes or DNx in B-ROLL: which menu option should you pick?#

Pick ProRes when your editor, client or finishing pipeline expects ProRes, and DNx when it expects DNxHR. B-ROLL handles both the same way, so the practical differences are bit depth and the tier each one lands on.

• ProRes: always 10-bit 4:2:2, on every tier. For a 1080p30 source at 8 Mbps it lands on 422 LT, with a reference rate of 102 Mbps.
• DNx: 8-bit 4:2:2 for 8-bit sources. For the same 8 Mbps source it lands on SQ, with a reference rate of 124 Mbps.
• DNx with a 10-bit source: always HQX, whatever the bitrate. B-ROLL’s estimate at 2160p60 is 188 x 8.008 = 1,506 Mbps, which is 11.3 GB per minute (1,506 x 60 / 8 / 1000).

A 10-bit source is where the two options split most. At 2160p60 with a 25 Mbps 10-bit source, ProRes lands on Proxy at 360 Mbps (45 x 8.008), while DNx goes to HQX at 1,506 Mbps: the ProRes file keeps 10-bit at about a quarter of the size. When no one downstream asks for DNxHR, ProRes is the lighter choice for 10-bit uploads.

HDR videos need one more step: yt-dlp prefers HDR streams by default, and B-ROLL applies no tone mapping during the conversion, so any HDR to SDR conversion happens in your editor.

On Windows, DaVinci Resolve reads both: the DaVinci Resolve 20 supported formats list shows ProRes and DNxHR in a .mov as decodable. The step-by-step import is in download YouTube videos for DaVinci Resolve, and the codec-level comparison is in ProRes vs DNxHR for editing.

Can you convert a file you already downloaded?#

No. B-ROLL has no converter for files already on disk: the ProRes and DNx conversion runs only on a download B-ROLL has just made. To get a .mov of an earlier MP4 download, download the video again with ProRes or DNx selected.

Paste the link again with ProRes or DNx in the Format menu. Different settings count as a new download, so B-ROLL does not stop at the “Already downloaded” dialog. The new .mov goes to your current download folder and the MP4 stays where it is.

The ↻ button on a finished card does the same from the list: it downloads the video again with your current settings, so choosing ProRes or DNx first gives you a .mov.

For a file that did not come from B-ROLL, use ffmpeg directly or your editor’s own transcode tools. B-ROLL starts from a YouTube link, not from a file.