7 minutes of UHD mp4 is...506 MB???

Hey all - just upgraded to Resolve 14 from 12.5 and so far it's absolutely fantastic.

Exporting a 7-minute project for a client in UHD/mp4 and was shocked to see that the file is only 506 MB........I was expecting 40 GB!! I went and looked at the render settings again: UHD, 23.976fps, "best" quality. The file does look pretty good when I play it back, but I don't have a 4k monitor so I can't tell if it's actually 4k or not. It's definitely at least 1080p, maybe 1440p. Maybe it is 4k!!

When I right-click on the exported mp4 and get properties/details, I get:

Length: 7:19
3840x2160
Data rate 9547kbps
Total bitrate 9665kbps
Frame rate 23
Item type MP4 file

What is going on??

Okay, as I was typing this I just re-exported the file as Quicktime/MPEG4 (which I thought was the same thing) and got a 3.79 GB file. Is this actually 4k? Or a grossly optimized variant of it? Is there a different format I should be using? I've used MOV or MP4 before for them and it's been fine - albeit MUCH larger files. I did a project last week (on Resolve 12.5) that was 2:10 and 13 GB (albeit 30fps)...so I'm scratching my head!

I just have a sinking feeling that I'm not actually delivering the 4k the client needs - this video will be edited into production shown on giant projection screens - so unlike most applications, 4k really matters here!

MANY thanks for the help!!!

Hi, My results for a UHD clip of 07'03 ''. To be compared.
(DR V14B4)

Code: Select all

Clip UHD : 7 min 03 s. Quality Best. Sound stereo.

                       size          Rendering time 
MP4_H264.mp4       11 802 881Ko          15:20   
QT_H264.mov        11 872 098Ko          15:15             
QT_MPEG4.mov        3 082 527Ko          03:41             

MEDIAINFO :
Général                                                             
Complete name                            : J:\H264\MP4_H264.mp4     
Format                                   : MPEG-4                   
Format profile                           : Base Media               
Codec ID                                 : isom (isom/iso2/avc1/mp41)
File size                                : 11,3 Gio                 
Duration                                 : 7 min 3s                 
Overall bit rate                         : 228 Mb/s                 
Writing application                      : Lavf57.25.100             
                                                                     
Vidéo                                                               
ID                                       : 1                         
Format                                   : AVC                       
Format/Info                              : Advanced Video Codec     
Format profile                           : Main@L5.1                 
Format settings, CABAC                   : Non                       
Format settings, ReFrames                : 2 images                 
Codec ID                                 : avc1                     
Codec ID/Info                            : Advanced Video Coding     
Duration                                 : 7 min 3s                 
Bit rate                                 : 228 Mb/s                 
Width                                    : 3 840 pixels             
Height                                   : 2 160 pixels             
Display aspect ratio                     : 16/9                     
Frame rate mode                          : Constant                 
Frame rate                               : 24,000 Im/s               
Color space                              : YUV                       
Chroma subsampling                       : 4:2:0                     
Bit depth                                : 8 bits                   
Scan type                                : Progressif               
Bits/(Pixel*Frame)                       : 1.146                     
Stream size                              : 11,2 Gio (100%)           
                                                                     
Audio                                                               
ID                                       : 2                         
Format                                   : AAC                       
Format/Info                              : Advanced Audio Codec     
Format profile                           : LC                       
Codec ID                                 : 40                       
Duration                                 : 7 min 3s                 
Duration_LastFrame                       : -5 ms                     
Bit rate mode                            : Constant                 
Bit rate                                 : 192 kb/s                 
Channel(s)                               : 2 canaux                 
Channel positions                        : Front: L R               
Sampling rate                            : 48,0 kHz                 
Frame rate                               : 46,875 Im/s (1024 spf)   
Compression mode                         : Avec perte               
Stream size                              : 9,84 Mio (0%)             
Default                                  : Oui                       
Alternate group                          : 1                         
---------------------------------
General                                                                                                                             
Complete name                            : J:\H264\QT_H264.mov 
Format                                   : MPEG-4               
Format profile                           : QuickTime           
Codec ID                                 : qt   0000.02 (qt  ) 
File size                                : 11.3 GiB             
Duration                                 : 7 min 3 s           
Overall bit rate                         : 230 Mb/s             
Writing application                      : Lavf57.25.100       
                                                               
Video                                                           
ID                                       : 1                   
Format                                   : AVC                 
Format/Info                              : Advanced Video Codec
Format profile                           : Main@L5.1           
Format settings, CABAC                   : No                   
Format settings, ReFrames                : 2 frames             
Codec ID                                 : avc1                 
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 7 min 3 s           
Bit rate                                 : 228 Mb/s             
Width                                    : 3 840 pixels         
Height                                   : 2 160 pixels         
Display aspect ratio                     : 16:9                 
Frame rate mode                          : Constant             
Frame rate                               : 24.000 FPS           
Color space                              : YUV                 
Chroma subsampling                       : 4:2:0               
Bit depth                                : 8 bits               
Scan type                                : Progressive         
Bits/(Pixel*Frame)                       : 1.146               
Stream size                              : 11.2 GiB (99%)       
Language                                 : English             
Color primaries                          : BT.709               
Transfer characteristics                 : BT.709               
Matrix coefficients                      : BT.709               
                                                               
Audio                                                           
ID                                       : 2                   
Format                                   : PCM                 
Format settings, Endianness              : Little               
Format settings, Sign                    : Signed               
Codec ID                                 : sowt                 
Duration                                 : 7 min 3 s           
Bit rate mode                            : Constant             
Bit rate                                 : 1 536 kb/s           
Channel(s)                               : 2 channels           
Channel positions                        : Front: L R           
Sampling rate                            : 48.0 kHz             
Bit depth                                : 16 bits             
Stream size                              : 77.5 MiB (1%)       
Language                                 : English             
Default                                  : Yes                 
Alternate group                          : 1                   
                                                               
Other                                                           
ID                                       : 3                   
Type                                     : Time code           
Format                                   : QuickTime TC         
Duration                                 : 7 min 3 s           
Time code of first frame                 : 01:00:00:00         
Time code, striped                       : Yes                 
Language                                 : English             
Default                                  : No                   
---------------------------------
General                                                         
Complete name                            : J:\H264\QT_MPEG4.mov
Format                                   : MPEG-4               
Format profile                           : QuickTime                                                                             
Codec ID                                 : qt   0000.02 (qt  )   
File size                                : 2.94 GiB             
Duration                                 : 7 min 3 s             
Overall bit rate                         : 59.7 Mb/s             
Writing application                      : Lavf57.25.100         
                                                                 
Video                                                           
ID                                       : 1                     
Format                                   : MPEG-4 Visual         
Format profile                           : Simple@L1             
Format settings, BVOP                    : No                   
Format settings, QPel                    : No                   
Format settings, GMC                     : No warppoints         
Format settings, Matrix                  : Default (H.263)       
Codec ID                                 : 20                   
Duration                                 : 7 min 3 s             
Bit rate mode                            : Constant             
Bit rate                                 : 59.5 Mb/s             
Width                                    : 3 840 pixels         
Height                                   : 2 160 pixels         
Display aspect ratio                     : 16:9                 
Frame rate mode                          : Constant             
Frame rate                               : 24.000 FPS           
Color space                              : YUV                   
Chroma subsampling                       : 4:2:0                 
Bit depth                                : 8 bits               
Scan type                                : Progressive           
Compression mode                         : Lossy                 
Bits/(Pixel*Frame)                       : 0.299                 
Stream size                              : 2.93 GiB (100%)       
Writing library                          : Lavc57.24.102         
Language                                 : English               
Color primaries                          : BT.709               
Transfer characteristics                 : BT.709               
Matrix coefficients                      : BT.709               
                                                                 
Audio                                                           
ID                                       : 2                     
Format                                   : AAC                   
Format/Info                              : Advanced Audio Codec 
Format profile                           : LC                   
Codec ID                                 : 40                   
Duration                                 : 7 min 3 s             
Duration_LastFrame                       : -5 ms                 
Bit rate mode                            : Constant             
Bit rate                                 : 192 kb/s             
Channel(s)                               : 2 channels           
Channel positions                        : Front: L R           
Sampling rate                            : 48.0 kHz             
Frame rate                               : 46.875 FPS (1024 spf)
Compression mode                         : Lossy                 
Stream size                              : 9.84 MiB (0%)         
Language                                 : English               
Default                                  : Yes                   
Alternate group                          : 1                     
                                                                 
Other                                                           
ID                                       : 3                     
Type                                     : Time code             
Format                                   : QuickTime TC         
Duration                                 : 7 min 3 s             
Time code of first frame                 : 01:00:00:00           
Time code, striped                       : Yes                   
Language                                 : English               
Default                                  : No                   


You do know that file size really just boils down to a single parameter: bitrate, don't you?

Your 500 Meg file is encoded at 10 Mbps, hence the size. The other clips you've provided metadata values are just encoded at higher bitrates (ranging from 50ish to 200ish). I'm pretty sure that when you made the mp4 deliver you had the quality box set to "restrict to 10000 kbps" which would explain your measured bitrate. When you picked another preset it is not surprising another target bitrate was picked too.

Now I would also be a little sceptic about such a small bitrate for broadcast delivery, especially if they're going to recompress the stuff to air it, but by all standards, it is "4K". The question is rather does it exhibit visible compression artefacts? My bet would be that it probably does, especially if you have motion in the picture. On an HD monitor, you could always play back the file at a 1:1 crop (just reimport it into Resolve or set the zoom in VLC/MPC type players) to check this.

I guess for mp4 delivery I would at least recommend the "youtube recommended upload settings", which states roughly 40 Mbps in 23.98p.

In my case: the 3 encodings are "automatic" + Best and unrestricted Kb / s. What lets me think that Gerry is also in automatic for the clip that gives a 3.79 GB file.

Guys, I can't thank you enough for these exceedingly helpful responses. Jean Claude, I am stunned that you actually took the time to export a similar-length project *three* times for me!! Thank you so much.

Alas, I was fully ignorant of bitrate...which is what happens when you have an amateur trying to learn a professional task!! It does make sense, though. So all of this is drone footage, and the raw files straight out of the camera are 60 MB/sec.

I just exported the project again to QT/264, "Best", and still got 10 MB/sec . BUT, I found an export I did last night that I put "QT" in the title of, and it's 70 MB/sec...(wonder where it's getting that extra 10 MB/sec that the original footage didn't have!) so at least I've got a good file to send the client now. It's 3-something GB, which is the same size as a raw file of comparable length right off the drone. I'll do some experimenting tonight and post my results back up. This is where being able to render just 5 seconds of the timeline is absolutely invaluable.

Thank you all so much again!

Hi Gerry,

I took advantage of an H264 test campaign that I do for myself to give you some results . I advise you to look at the link given by Forest Finbow if your clip is intended for youtube. I also advise you to see on the side of Vimeo that I find a little better: Uploading to Vimeo - Help Center

Sure enough, Jean Claude - and I truly appreciate it! Just trying to confirm if there's some strange issue on my side.

So I just did some 6-second exports under "Custom" of QT/264/MPEG/MP4 codecs and I'm getting bitrates of either 188MB/sec or 80 MB/sec.......so then I tried the same thing first clicking on "YouTube" rather than "Custom"...and the 10 MB/sec was back! So the moral of the story is even though you can deselect "Restrict to 10 MB/sec" and click "Best" under "YouTube," you're still looking at 10 MB/sec - and maybe for YouTube that's okay; I figure why else would Resolve do that. If a file is going to YouTube, is it worth it to do a higher-bitrate render?

Many thanks for helping me get to the bottom of this - I appreciate you all very much!!

If you're really going to project this material on a giant production screen, you might want to consider compressing to x.264 in another application, like Handbrake, which gives you precise control over the data rate and is likely to do a better job than Resolve. As has been pointed out here many times, Resolve doesn't revolve around h.264 and other long GOP formats. It's not designed for youtube.

The thing would be to export in Resolve to Cineform, Prores, DNxHR, etc. at "best" quality and then do the compression elsewhere.

Sure enough, Jean Claude - and I truly appreciate it! Just trying to confirm if there's some strange issue on my side.

So I just did some 6-second exports under "Custom" of QT/264/MPEG/MP4 codecs and I'm getting bitrates of either 188MB/sec or 80 MB/sec.......so then I tried the same thing first clicking on "YouTube" rather than "Custom"...and the 10 MB/sec was back! So the moral of the story is even though you can deselect "Restrict to 10 MB/sec" and click "Best" under "YouTube," you're still looking at 10 MB/sec - and maybe for YouTube that's okay; I figure why else would Resolve do that. If a file is going to YouTube, is it worth it to do a higher-bitrate render?

Many thanks for helping me get to the bottom of this - I appreciate you all very much!!

Uh ... when you click on the preset:
Youtube 720p: look at the resolution => 1280x720 HD 720p.
Youtube 1080p: look at the resolution => 1920x1080 HD 1080p.

For UHD, you start with CUSTOM => you rules your good parameters and at the end you click on the 3 small points in the top right (see image)

P1.jpg

And you will have a menu that will allow you to enter a name and save your preset.

P2.jpg

The following times, you will have to click on it and all your parameters will be present.

P3.jpg

It is necessary to read the manual ... It is tedious but this is where we learn best ... (in my opinion)

John, that's a great idea. I'm exporting clips DNxHR HQX 12-bit (any reason to choose 10-bit instead?), then I'll use Handbrake to convert them. Any reason I shouldn't use 60 MB/sec bitrate, which is the same bitrate as the original footage?

Jean, I never knew I could make my own presets! It was a bit confusing because if I'd clicked "YouTube" it would stay highlighted (and lock my bitrate) even though allowing resolutions higher than 1080p. Very helpful!

Can't thank you all enough - this is absolutely changing my workflow for the best!

PS - for the times that the footage is headed to YouTube, should I use the Resolve presets (which lock bitrate) - any reason to upload higher-bitrate footage?

Okay, so I've now tried QT/DNxHR HQX, QT/Cineform RGB 16-bit, and AVI Cineform YUV 10-bit, and when I open them in Handbrake, it tells me "No valid source or titles found." Any ideas??? Surely Handbrake supports these file formats?!?

Handbrake isn't meant for professional formats and it might actually be that it doesn't support those.

PS - for the times that the footage is headed to YouTube, should I use the Resolve presets (which lock bitrate) - any reason to upload higher-bitrate footage?

I generally do my Web/YT/Vimeo compression with Adobe Media Encoder. While it is not the best one out there it features very decent quality with single or 2 pass VBR and it allows for preprocessing (fps/interlacing change, colorspace conversion, timecode burning etc...) which turns out to be very useful for me.
For the sake of argument, if you have access to it I would encourage you to compare something extreme like a 2 Mbps HDTV (or a 6 Mbps 4K) compression with 2 pass VBR enabled in AME vs Resolve CBR restricted to the same bitrate (2000 or 6000kbps), you'll be surprised to see how compression handling can seriously impact picture at low bitrates.

Now this being said, online services generally recompress et reprocess the footage sent to them: YouTube, for example, will further denoise and drastically reduce bitrate so you don't want to upload something as fragile as the test I suggested above. For short jobs I actually don't hesitate to send ProRes 422 HQ files and let youtube do the compression (since it will recompress no matter what). If the job is too long and prores is not practical then I'll go with 120% of the youtube recommendations linked above. Either case, this is not the bitrate the youtube preset in Resolve will give you for 4k so I would advise you to write a new preset or go third party such as I do.

John, that's a great idea. I'm exporting clips DNxHR HQX 12-bit (any reason to choose 10-bit instead?), then I'll use Handbrake to convert them. Any reason I shouldn't use 60 MB/sec bitrate, which is the same bitrate as the original footage?

For a youtube export frankly even 10 bits is kind of unnecessary unless you are uploading HDR footage. But for mastering, if your footage was 12 bit RAW, then yes, by all means, save it as 12 bits!

As to your question, where does 70 Mbps come from when the footage was only 60, you have to rethink what compression is.
Starting with uncompressed video: your footage, at creation level is not 60 mbps, it is actually much much bigger.
If it is 4K RAW, then it is 3840x2160x12x23.98 = 2884045824 bps, or 2750 mbps.
If it is 4K 8bit RGB, then it is 3840x2160x8x3x23.98 = 4773593088 bps or 4552 mbps.
As you can see, 4K footage is multi Gigabits/s material.
Modern compression techniques are clever, very clever. Your onboard camera compression will thus compress this data to a fraction of its initial space requirement and that's good, it means you can fit it onto a fairly small memory card.
The first thing your editing software will do however is decompress the video back to its initial size to process it. Your GPU and CPU actually handle those Gbps, as does your compressor when you deliver your file. There is no reason for the final compressor to match the initial camera set bitrate. If you've paid attention above, different techniques yield different result for the same bitrate so trying to match it is really irrelevant.

Gerry, that 10Mbps in the YouTube tab is merely the default. You can change it to whatever you wish. My camera originals are 35Mbps, so when doing a final render I set the restrict bitrate to 35Mbps to maintain the quality.

It appears Handbrake is currently limited to Prores and DNxHD, which doesn't look like it will get you to 4K on a PC. You'll need to find something else.

This is all incredibly helpful, all. I went ahead and rendered with Resolve to get the project to the client; I went with 60 MB/sec though I offered to redeliver at the full 180 MB/sec if they wished. I wonder just what the visible difference is! I may be finally getting a 4k TV next week...might finally find out for myself what all the fuss is

I'll stay tuned for a better workflow than I'm currently using (as I've been too cheap to shell out for Adobe software!); Resolve does just keep getting better and better and surely Handbrake will eventually support all those formats - I would assume!!

Many, many thanks for all the help! You guys truly are great.

Okay, so I've now tried QT/DNxHR HQX, QT/Cineform RGB 16-bit, and AVI Cineform YUV 10-bit, and when I open them in Handbrake, it tells me "No valid source or titles found." Any ideas??? Surely Handbrake supports these file formats?!?

I usually do uncompressed 10 bit YUV AVI, when I go to Handbrake, to insure best possible quality and avoid artifacts from an other compression step. Works like a charm.

Actually I record uncompressed raw, stay uncompressed during post, and do an uncompressed master.
Some say, that's an overkill. Well maybe, but hard drives are dirt cheap this days, and why would I want anything less, than the best possible quality. Most of the stuff going on in front of my camera is way more expensive, so I don't cheap out on data rate/storage.

This is all incredibly helpful, all. I went ahead and rendered with Resolve to get the project to the client; I went with 60 MB/sec though I offered to redeliver at the full 180 MB/sec if they wished. I wonder just what the visible difference is! I may be finally getting a 4k TV next week...might finally find out for myself what all the fuss is

I'll stay tuned for a better workflow than I'm currently using (as I've been too cheap to shell out for Adobe software!); Resolve does just keep getting better and better and surely Handbrake will eventually support all those formats - I would assume!!

Many, many thanks for all the help! You guys truly are great.

Hi Gerry,

When I do some encoding tests for the MP4 / H264, I often use clip where you see reflections on the water with very slight wavelet. It's pretty redoudable for encoders ... When there is no more macroblock ... You will have an indication for the right bitrate.

I usually do uncompressed 10 bit YUV AVI, when I go to Handbrake, to insure best possible quality and avoid artifacts from an other compression step. Works like a charm.

Did you manage to get Handbrake to convert 4K uncompressed to 4k x.264? That had occurred to me as a possible solution for the OP. So I tried it, but couldn't get the output resolution in Handbrake to exceed 1080p.