-
Exporting long H.264 sequences from FCP7, any tips?
Hello. I have exercise videos which are 45-minutes long ready for exporting in a FCP7 HD project (ProResLT 1920×1080 25fps). They will be used just for the web. I am aware that they will need to be heavily compressed and therefore image quality will be compromised, but I am wondering if there are any particular tips/settings for getting the best quality at a reasonably low file size? Also, how big a file can I go to before it becomes troublesome to stream online?
I have done some test one-minute exports at data rates of 5000 and 3500 k bits/sec (HD 1280×720), but these have indicated that the final file size will be around 16GB and 12GB respectively, which I believe is far too big for web streaming. Do I simply have to compress the hell out of them until I get a file size of less than 1GB?
Any advice would be greatly appreciated.
-
7 Replies
-
Export from FCP in the same settings as the timeline, then convert it to whatever you’re going to deliver with something like Compressor – software which is made for the job will be much faster for doing the compression than FCP and have options that’ll improve the quality if you go into the settings menu(s).
Remember that in full quality editing we don’t pay too much attention to the size of the sound because it’s so much smaller than high quality video, but it does make a difference when things are highly compressed, so when working out what data rate to use it might be worth taking the audio data rate down as well as the pictures, perhaps as far as 96k (but do some tests and be critical over how it sounds – cruddy sound is worse for the audience’s experience than iffy picture quality).
Once you’ve worked out the data rate you need, do the compression with multi-pass selected. It takes longer than single pass (it can take twice as long or more) but the perceived quality at a given data rate is significantly better for most material.
-
[Andy Oxley] “I have done some test one-minute exports at data rates of 5000 and 3500 k bits/sec (HD 1280×720), but these have indicated that the final file size will be around 16GB and 12GB respectively,”
Andy, I think your math is a bit off. Supposing a h.264 codec, if your video is 45 minutes long and you encode at 5000Kbps (both audio and video combined total), your total file size would be just under 2GB (about 1.7GB). If you run it at 3500Kbps then you’re looking at a file size of about 1.2GB.
Use a file bandwidth to filesize calculator if you want to easily experiment with different data rates:
https://web.forret.com/tools/filesize.asp?speed=5000&unit=Kbps&dur=2700But as Andrew mentioned, if you can afford the extra time a 2-pass VBR will usually net a better overall picture and lower overall file size as it more efficiently utilizes the given data rate.
Ryan Holmes
http://www.ryanholmes.me
@CutColorPost -
Slightly OT, but, I recently picked up the Matrox CompressHD card for my Mac tower. Incredible speed increase (like 4x faster, about real-time) on H264 encoding vs. the normal Compressor. Well worth the $500. in time savings alone! Just passing it along. I was glad someone told me about it.
Ernie Santella
Santella Productions Inc.
http://www.santellaproductions.com -
I second the Matrox CompressHD (or MAX enabled MXO2 device) recommendation for accelerating h.264 encoding.
-
Andy, you’re probably exporting at 5,000 Mbps, not Kbps. 1Mbps = 1000 Kbps.
Export a 45-min ProRes Lt movie from Final Cut Pro with “Export as QuickTime Movie”. This is a huge file.
Bring that QuickTime into compressor, apply these settings and it will probably be about a gig and look great:
-H.264, 1280×720, current frame rate, 1000 KBPS
I would say test different compressions from 700kbps to 1500 Kbps and see what your sweet spot is for file size and quality. Anything around 1000 should look good and be under a gig. And definitely do the longer 2-pass compression.
-
[Ryan Holmes] “Andy, I think your math is a bit off”
Yes, you and Spencer are both correct on that front, how embarrassing! I was a decimal point out in my calculations. Nevertheless, still very useful advice from everyone, I will try these methods out and see how it goes. Thanks very much everyone.
-
[Spencer Averick] “Andy, you’re probably exporting at 5,000 Mbps, not Kbps.”
Sorry, but your maths are a bit off as well.
1920×1080 10b Uncompressed YUV/422 is around 1.200 Mbps (1.2 Gbps).
With 5.000 Mbps you could stream 4K10b Uncompressed YUV/422.
5.000 Kbps is OK for DVDs MPEG2 or web H264.
rafael
Reply to this Discussion! Login or Sign Up