Exporting at Exact Bit Rate for Deliverable. Urgent :(

Forum|Forum|6 years ago
September 27, 2019
4 replies
3153 views

Hi there,

I need to deliver a music video to my client for distribution on iTunes. Apparently, iTunes have quite specific specifications - they need a bit rate of ~220 Mb/s (plus 1080p Apple ProRes 422 HD). But my video is only 164.9Mb/s. Does anyone know how to increase the bit rate without increasing resolution?

More info:

I worked with Arri Alexa footage in Premier, then exported at ProRes 422 HD, then graded in Davinci Resolve and exported again at ProRes 422 HD. The iTunes specs are below:

File Format : QuickTime (.mov files)
Codec : Apple PRO RES 422 (HQ)
Size : 1920x1080 pixels
Video Bitrate : ~220 Mb/s
Framerate : 24 or 25 fps
Colorspace : YUV 422

This topic has been closed for replies.

S

Steve Griffiths

Inspiring

The 220 megabits per second referenced in the iTunes specs refer to the the maximum bitrate available for use by the Prores HQ codec. Prores is a 'variable bit rate codec'. In real life and depending on the visual complexity of your video your actual datarate will vary and generally not hit the maximum of 220Mb/s.

I just did a test export with Prores 422 HQ and mananged to get 176Mb/s on one scene and 71Mb/s on another (both same duration). The 2nd being a much simpler scene (visually).

However I see you are exporting in standard Prores 422 - the spec asks for Prores 422 HQ. I'd advise using the HQ version for your final export out of Premiere Pro.

Q

Qengineering

Inspiring

The different ProRes codecs are different bit rates

ProRes Proxy (lowest) < ProRes LT < ProRes < ProRes HQ < ProRes 4444 < ProRes 4444 XQ (highest)

If they specify a codec (i.e. ProRes HQ) use that and you're done, bit rate is set by the codec.

If they DON'T specify a codec, try each until you get the desired bit rate.