ref frames

I'm trying to get the exported mp4/H.264 file to have 4 ref frames. The original has 4, but when I export it it only has 2. I'm very new to DaVinci Resolve, so I don't know all of the settings. I have tried multiple settings, but with now luck. Is there a way to change the exported ref frames? and if so how would I do it?

Is there a way to change the exported ref frames?

No, I'm afraid there isn't. It's fixed at 2. Added to which the H264 GOP structure is 'Closed' and there is no CABAC entropy coding - CAVLC only.

If you want higher quality (compression efficient), configurable H264 encoding you'll need to export to an intermediate format and use an external (x264) encoding tool - FFMPEG, Handbrake, VirtualDub2 etc.

Thanks for the information.
What intermediate format would you recommend to keep loss at a minimum?

Is there a way to change the exported ref frames?

No, I'm afraid there isn't. It's fixed at 2. Added to which the H264 GOP structure is 'Closed' and there is no CABAC entropy coding.

If you want higher quality, configurable H264 encoding you'll need to export to an intermediate format and use an external (x264) encoding tool.

Thanks for the information.
What is the best intermediate format to use without loosing data/quality?

None of the 'intermediate' codecs are completely (i.e. mathematically) lossless, but depending on the OS you are running Resolve on, any of the 10-bit 422 export codecs - Cineform, DNxHD/DNxHR HQX, Grass Valley HQX, Prores HQ - will be perfectly acceptable. Set for 'Best' quality if so desired, but expect larger file sizes.

Also depends on whether the 'intermediate' codec is compatible with the x264 encoding tool of choice. FFMPEG, for example will accept all of these formats. VirtualDub2 also. But Handbrake won't accept DNxHR or Cineform for input.

What's the source of your H264.mp4 footage, out of interest ?

Is there a way to change the exported ref frames?

No, I'm afraid there isn't. It's fixed at 2. Added to which the H264 GOP structure is 'Closed' and there is no CABAC entropy coding - CAVLC only.

If you want higher quality (compression efficient), configurable H264 encoding you'll need to export to an intermediate format and use an external (x264) encoding tool - FFMPEG, Handbrake, VirtualDub2 etc.

@Brian not sure(?),

Either you do not have to have the Studio version or you have not explored the NVIDIA option or you do not have a graphics card with CUDA

Export QT / H264 Native => REF FRAME is:

Code: Select all

Video
ID: 1
Format: AVC
Format / Info: Advanced Video Codec
Profile format: Main @ L4
Format settings: 2 Ref Frames
CABAC settings: No
Format settings, RefFrames: 2 frames


Export QT / H264 NVIDIA => is:

Code: Select all

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : High@L4
Format settings                          : CABAC / 4 Ref Frames
Format settings, CABAC                   : Yes
Format settings, RefFrames               : 4 frames


High/main....

Is there a way to change the exported ref frames?

Export QT / H264 NVIDIA => is:

Code: Select all

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : High@L4
Format settings                          : CABAC / 4 Ref Frames
Format settings, CABAC                   : Yes
Format settings, RefFrames               : 4 frames


High/main....

Well, there you go, I was wrong.

@Nathan. Still, I hope you find the advice about the 'intermediate' formats useful if you need to go that route.

Is there a way to change the exported ref frames?

Export QT / H264 NVIDIA => is:

Code: Select all

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : High@L4
Format settings                          : CABAC / 4 Ref Frames
Format settings, CABAC                   : Yes
Format settings, RefFrames               : 4 frames


High/main....

Well, there you go, I'm wrong.

Still, I hope you find the advice about the 'intermediate' formats useful if you prefer to go that route.

But the best is the H265 + NVIDIA for the HDR ... ... did you try?

No I haven't.

Thanks everyone. I’ll give that a try.

Is there a way to change the exported ref frames?

Export QT / H264 NVIDIA => is:

Code: Select all

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : High@L4
Format settings                          : CABAC / 4 Ref Frames
Format settings, CABAC                   : Yes
Format settings, RefFrames               : 4 frames


High/main....

Where would I input that into?

The 'NVIDIA' option is only available in the Studio version.

@Nathan,
BTW - If you're not on the Studio version, external NVIDIA GPU encoding (NVENC) is also possible with FFMPEG through the h264_nvenc and hevc_nvenc encoders:

https://trac.ffmpeg.org/wiki/HWAccelIntro

I believe Handbrake now supports NVENC encoding also. I don't use it myself.

ok thanks. I think eventually I will get the studio version, but until then I will try your ideas.

Export QT

He was asking about the far more ubiquitous MP4, which doesn't offer all of the the needed controls yet.

Export QT

He was asking about the far more ubiquitous MP4, which doesn't offer all of the the needed controls yet.

@Jim not sure(?), with v15.2.1

Either you do not have to have not explored the NVIDIA option or you do not have a graphics card with CUDA?

Export MP4/ H264 NVIDIA ENCODING PROFILE HIGH => REF FRAME capable is:

Code: Select all

General
Complete name                            : G:\Temp\MP4\MP4_NVIDIA.mp4
Format                                   : MPEG-4
Format profile                           : Base Media
Codec ID                                 : isom (isom/iso2/avc1/mp41)
File size                                : 32.7 MiB
Duration                                 : 16 s 800 ms
Overall bit rate                         : 16.3 Mb/s
Writing application                      : Lavf57.25.100

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : High@L4
Format settings                          : CABAC / 4 Ref Frames
Format settings, CABAC                   : Yes
Format settings, RefFrames               : 4 frames
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding