Blackmagic Forum

Hi,

why does DR deliver at higher bitrate than my footage?
Isn't that plain wrong?

You control the export. Set the bitrate to what you want/need it to be.

That can happen, depending on codec and image quality. Which one did you use?

I've always used "Quality: Automatic - Best"

Maybe I can set the bitrate manually next time..

Depends on your settings and the encoder used.
The 'Native' encoder in Resolve when set to 'best' has a habit of cranking up the kbps.
Example: source 20,000 kbps - export at 'best' 180,000 kbps.
I never use 'best' with the Native encoder because of this.
Select the desired kbps in the settings.
If you have an Nvidia card, the Nvidia encoder often works better, and it's 'best' settings are reasonable.
But again, I select the kbps for export.

capthook wrote:The 'Native' encoder in Resolve when set to 'best' has a habit of cranking up the kbps.

In my testing, I find this setting comparable in quality and size to using x264 CRF 16.

That's reeeeally good, so those bitrates aren't surprising.

capthook wrote:If you have an Nvidia card, the Nvidia encoder often works better, and it's 'best' settings are reasonable.
But again, I select the kbps for export.

I do have a GTX Card but when selecting mp4 as container I'm only getting H.264 as codec: should it be NVENC instead?

roughnecks wrote:should it be NVENC instead?

To use the nVidia card for encoding, yes.

Jim Simon wrote:

roughnecks wrote:should it be NVENC instead?

To use the nVidia card for encoding, yes.

So this feature is not in Davinci Resolve?

Studio version only, not Free version.

Jim Simon wrote:Studio only.

I see, thanks

Don't be too sad. While the Native encoder is significantly slower, I do find it produces better results.

roughnecks wrote:Hi,

why does DR deliver at higher bitrate than my footage?
Isn't that plain wrong?

Not at all. All cameras including the high end ones capture using some sort of compression. The final archival masters are nearly always delivered uncompressed and as such have a significantly higher bandwidth than the sources.

Igor Riđanović wrote:

roughnecks wrote:Hi,

why does DR deliver at higher bitrate than my footage?
Isn't that plain wrong?

Not at all. All cameras including the high end ones capture using some sort of compression. The final archival masters are nearly always delivered uncompressed and as such have a significantly higher bandwidth than the sources.

Sorry but if you have an MP3 and convert it to WAV, which is uncompressed, you aren't getting any better quality than the MP3's, even if the bandwidth is higher.

Isn't this the same?

roughnecks wrote:

Igor Riđanović wrote:Sorry but if you have an MP3 and convert it to WAV, which is uncompressed, you aren't getting any better quality than the MP3's, even if the bandwidth is higher.

Isn't this the same?

Compression errors are cumulative. Copying the file (or stream) will not result in quality loss, but as soon as you make any change the stream has to be decompressed and re-compressed. Video and audio editors generally assume changes will be made so always re-compress.

roughnecks wrote:

Igor Riđanović wrote:

roughnecks wrote:
Sorry but if you have an MP3 and convert it to WAV, which is uncompressed, you aren't getting any better quality than the MP3's, even if the bandwidth is higher.

Isn't this the same?

I get your question. I can't speak to audio although I imagine similar forces are in effect as with video.

Let's say your source media is H.264 and you are rendering a fade to black. The visual rendition of this fade will be better in uncompressed 10 bit video than in compressed 8 bit video that matches the source. Any changes in levels you introduce stand to benefit to some extent from a non-compressed high bit-depth recording.

If you are using the free version on a PC, export a high-quality master and do the final compression in Handbrake (free).
Much better ratio of size to quality.