mp4 to DNxHd - File size 10x larger

[blizzard]

Hey All,

I am receiving mp4 from my director and have been converting to QT using H264. After reading more about which codec to use I am experimenting with DNxHD. When using Streamclip to convert to DNxHD the file size is increasing ten-fold. From 99MB to 9GB!

Is there a better way to convert these? Any specific settings I should be trying? Avid talks about how DNxHD allows smaller file sizes for ease of use but I am not seeing that at all.

Thanks for any help you can offer.

[YMAaron]

Originally Posted by blizzard

Hey All,

I am receiving mp4 from my director and have been converting to QT using H264. After reading more about which codec to use I am experimenting with DNxHD. When using Streamclip to convert to DNxHD the file size is increasing ten-fold. From 99MB to 9GB!

Is there a better way to convert these? Any specific settings I should be trying? Avid talks about how DNxHD allows smaller file sizes for ease of use but I am not seeing that at all.

Thanks for any help you can offer.

That's the standard size for a 30 minute programme I'm afraid. Nothings going wrong - that's just how it is!

[Craig F]

mp4/h264 have a key frame then a bunch of change data instead of frames, the change data is CPU intensive to recreate the missing frames

when DNxHD or Pro Res is talked about, they're are taking about down from the RAW uncompressed camera data

[Speedsound]

Hi,

try DNXHD 36 8bit
It should be lighter...

Originally Posted by blizzard

Hey All,

I am receiving mp4 from my director and have been converting to QT using H264. After reading more about which codec to use I am experimenting with DNxHD. When using Streamclip to convert to DNxHD the file size is increasing ten-fold. From 99MB to 9GB!

Is there a better way to convert these? Any specific settings I should be trying? Avid talks about how DNxHD allows smaller file sizes for ease of use but I am not seeing that at all.

Thanks for any help you can offer.

[blizzard]

Originally Posted by YMAaron

That's the standard size for a 30 minute programme I'm afraid. Nothings going wrong - that's just how it is!

That's the thing, these are 6 minutes max.

Originally Posted by Speedsound

Hi,

try DNXHD 36 8bit
It should be lighter...

Sorry for the delay in posting...I have been busy with this:

http://duc.avid.com/showthread.php?t=364338

I have reformatted my Windows 7 machine from scratch and still have some issues with PT freezing. I want to make sure that I eliminate as many possible video engine related problems (if not all of them...haha) to help determine what is causing my instability.

I don't have the option for 36 8-bit in MPEG Streamclip. I have the following

720p/23.976 DNxHD 90 10-bit
720p/23.976 DNxHD 90 8-bit
720p/23.976 DNxHD 60 10-bit

Also are there any additional settings within Streamclip that would help in PT? Frame size/blending, Alpha compression, etc... Working with Video is still somewhat new to me within PT.

[tom_lowe]

Originally Posted by blizzard

That's the thing, these are 6 minutes max.



Sorry for the delay in posting...I have been busy with this:

http://duc.avid.com/showthread.php?t=364338

I have reformatted my Windows 7 machine from scratch and still have some issues with PT freezing. I want to make sure that I eliminate as many possible video engine related problems (if not all of them...haha) to help determine what is causing my instability.

I don't have the option for 36 8-bit in MPEG Streamclip. I have the following

720p/23.976 DNxHD 90 10-bit
720p/23.976 DNxHD 90 8-bit
720p/23.976 DNxHD 60 10-bit

Also are there any additional settings within Streamclip that would help in PT? Frame size/blending, Alpha compression, etc... Working with Video is still somewhat new to me within PT.

DNxHD36 is oddly only available for 1080P footage. And it's simple mathematics. Those settings are 90Mbps and 60Mbps, your MP4 could only be 5-6Mbps, so a 10x increase is correct.

[smurfyou]

Is the file size a problem? A 20+GB DNx will play much better than a 1GB MP4. Its not the size, its the codec that matters.

[blizzard]

Okay this is all making much more sense now. And I am noticing so far that the larger DNxHD does really play better that the smaller. My learned habit of smaller file size = faster playback is hard to kick.

Thanks for the advice everyone.

[YMAaron]

Originally Posted by blizzard

Okay this is all making much more sense now. And I am noticing so far that the larger DNxHD does really play better that the smaller. My learned habit of smaller file size = faster playback is hard to kick.

Thanks for the advice everyone.

Yes but remember don't go too far as surely you're putting massive strain on your hard drive reading that amount of data to play the video. You do have a separate video drive don't you?

[blizzard]

I have two SSD that host my samples for all my VI's, and I keep all my video that I'm scoring to on one of those. I'm thinking of getting another SSD soon though, and will likely use it for video and rarely used samples.