Ivan Myles
Forum Replies Created
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Ivan, were all the luma values between 0-100 IRE?
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Were any colorization effects applied to the clip?
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Does this help? Specify and apply default transitions
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H.264 will provide the best image quality at low bitrates.
Fitting a 10 minute movie into 50MB will require an average total bitrate of 667 kbps. If audio is set to 128kbps, that leaves 440kbps for video. Export a short test file at different frame rates and resolutions. For reasonable image quality start with 360p and 240p square pixels. If the image is not satisfactory try one or more of the following: 240p/360p with rectangular pixels, 180p square pixels, reduced frame rate (50%), or increased bitrate.
Here are some other settings:
– Main or High profile
– Level 1.3
– VBR 2-pass
– Target bitrate: 440
– Maximum bitrate: 640 (anywhere from 440-768 should work)
– Disable: Key Frame Distance
– Enable: Use Maximum Render Quality -
It would be helpful if more information was provided regarding the loss of quality. Is the primary issue banding/blocking? Luma/chroma shifts? Loss of detail in bright and dark areas? Jagged lines? Other?
Banding/blocking: maximize Intra DC Precision in the Advanced MPEG-2 options, and increase the Minimum Bitrate setting.
Color shifts: avoid RGB intermediate formats. You could apply offsets to the sequence with the RGB Color Corrector, but it is probably not worth the effort at this point.
Lack of bright/dark details: view the footage in the YC and RGB Parade scopes to ensure values are in the 0-100 IRE range. This will be noticeable in the sequence; it is not a byproduct of rendering.
Jagged lines: enable Use Maximum Render Quality.
Refer to the hardware specs and/or run a few test files in advance to verify the configurations supported by the Toshiba display. The conservative option is to use one of the MPEG-2 presets and change bitrate to 20mbps.
1920×1080 at 20mbps should/might be OK. Consider rendering another copy at 1440×1080 (widescreen 1.333) and/or 1280×720 (square pixels 1.000) and let the display scale it up during playback.
Use VBR 2-pass encoding.
GOP structure of M=3 and N equals 0.5 or 1.0 seconds (converted to frames) is typical for MPEG-2. Longer GOP lengths are OK, but you don’t gain much past one second. Closed GOP (equal to N) and automatic GOP placement are preferred.
You might not have enough time, but MPEG2 can be “tuned.” Filesize can be reduced sometimes through an iterative process of increasing and decreasing the bitrate targets to find the point where the data is compressed most efficiently.
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Other items to check include program monitor scaling (100%), playback quality (full), and sequence preview codec. Also try exporting a short clip to verify the render quality.
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You are best off calling an attorney to advise whether it is permissible, and, if appropriate, to write a release or disclaimer. Consider passing on the project if current/future incremental revenue doesn’t cover the legal fees.
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[Ivan Myles] “default set to 6000 mbps”
Sorry for the typo. Should be 6000 kbps.
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[Sean Winn] “Where do you suggest I set the bitrate – or is the picture what you’re suggesting (6000)?”
Yes, click on the the orange text (default set to 6000 mbps) and enter the desired target bitrate.
[Sean Winn] “When I set it to quicktime, h.264, and change the size to 1280×720 (while linked) it won’t accept it and changes from 1280 to 1080 for example.”
This happens sometimes, usually when changing the aspect ratio. Just unlink and set the dimensions as required.
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Check each of the following parameters:
– Track mute in the Program panel
– Volume setting in the Effect Controls panel for the clip
– Audio Gain… under the menu item Clip > Audio Options (or right click the clip)
– Track mute in the Audio Mixer panel
– Track audio level in the Audio Mixer panel
– Master audio level in the Audio Mixer panel