Same as First Video Clip/ MTS/AVCHD

[newfielander]

Hi friends I'm editing MTS files/AVCHD. Footage filmed with a panasonic cam, using Pro 6, when I hit share tab - create video file - I have many choices but I would like to save it as high format as the original, so do I hit , (Same as First Video Clip) or (AVCHD) both are nearly the same I'm guessing, I've saved in both formats and both ended up been the same size. Any suggestion on what one I should save to ? I have added the properties of the original file.
Thanks

[lata]

Hi

Same as First Video Clip is my choice, this would retain your 5.1 audio surround sound, the default templates using stereo, otherwise the template is very similar.

[newfielander]

Hi lata, did notice that the Video Data Rate was higher on the AVCHD template,the (Same as first video clip) is Video data rate: Variable (Max. 16800 kbps)
AVCHD is Video data rate: Variable (Max. 18000 kbps) ,so will this give me a little better video??
Thanks

[lata]

Hi

Using an 18000 kbps instead of 16800 will not improve the quality. (post edited 18000)
Besides loosing your audio properties.

You are best to retain your original settings, rendering will be quicker.

As you seem to need to improve quality have you a problem with the originals.

Run a test to check both options, let us know which is the best.
Ok so I did just that and something strange happened, choosing AVCHD (top option) clearly shows as using 18000 yet the new video used 16800kbps, same as original.
How odd…….
Just to confirm each time I use Share Avchd I get 16800kbps
Don’t ask, cos I don’t know? These are the two properties

Share AVCHD
MPEG Transport-Stream Files
24 bits, 1920 x 1080, 25 fps
Upper Field First
(HDMV-PAL), 16:9
H.264 Video
Video data rate: Variable (Max. 18000 kbps)
Audio data rate: 384 kbps
Dolby Digital Audio, 48 KHz, 2/0(L,R)

Share Same as
PAL (25 fps)
MPEG Transport-Stream Files
24 bits, 1920 x 1080, 25 fps
Upper Field First
(HDMV-PAL), 16:9
H.264 Video
Video data rate: Variable (Max. 16800 kbps)
Audio data rate: 256 kbps
Dolby Digital Audio, 48 KHz, 2/0(L,R)

[newfielander]

Hi Lata, you said,"Using an 1800 kbps instead of 16800 will not improve the quality." You meant 18000 kbps right ?

[Ken Berry]

While lata can reply for himself, that is obviously what he meant. Just increasing a bitrate from one which is lower cannot improve the original quality. Indeed there is a risk of slightly decreasing the quality. That is because all varieties of mpeg -- and AVCHD is an mpeg-4 created with the h.264 codec -- are lossy. Each re-render of an mpeg will cause a little loss in quality. And changing a bitrate upwards will involve a re-render. The quality loss may be small, and perhaps not even detectable to the human eye, especially if it is only one re-render and when dealing with HD video, but it will be there nonetheless. So as lata recommends, stick with your original bitrate.

[newfielander]

Hi Ken ,yes that was my mistake I total understand.

[lata]

Hi

I add a HD video to the timeline, property details in previous post, It’s a standard Panasonic 900 sample.

What I don’t understand is why when choosing Share Create Video File – Avchd 1920 x 1080 does the resultant video clip use 16800kbps

I haven’t had time to follow this up but the results are strange to say the least.
Unless I misread 16800 for 18000 ish.

anyone wish to confirm this?

[newfielander]

Hi Lata I'm using ProX6 when I click , Share Create Video File – Avchd 1920 x 1080 here's the properties I get.
MPEG Transport-Stream Files
24 bits, 1920 x 1080, 29.97 fps
Upper Field First
(HDMV-NTSC), 16:9
H.264 Video
Video data rate: Variable (Max. 18000 kbps)
Audio data rate: 384 kbps
Dolby Digital Audio, 48 KHz, 2/0(L,R)

[lata]

Yes, I see the same properties but Pal version.

Maybe you misunderstand.

When I add a clip to the timeline (unedited) using 16800kbps, then share Create Video File AVCHD 1920 x 1080, the template should be using 18000kbps, but after rendering the new video file uses 16800kbps.

If I edit the clip by say removing a few frames then 18000kbps is used.

[newfielander]

Ok now I understand, its a good question.

[tommy12]

Hi lata,

If I understand you correctly, your template always says 18000 kbps but your output can be 16800?

FWIW: I tested a Nikon DSLR h264.mov 1920 x 1080p 30fps clip and got this result.

Using MediaInfo for the clip properties:

The original clip is 21.7 (variable) Mbps video. After Share\AVCHD\1920x1080 30fps it is 16.7 Mbps (variable)/ 18.0 Mbps Max.

After adding a dissolve to the end of the original clip, and sharing to the same selection, it becomes 18.5 Mbps (variable)/ 18.0 Mbps Max.

I don't think it has any affect on the output bitrate, but the output video is always progressive like my original, even though the share preset template is set to upper field first. I assume that AVCHD from a camcorder is interlaced upper field first.

Edit:
I'm new to video editing, so I'm probably wrong about this. Is the template bitrate the Maximum bitrate, not necessarily the actual bitrate you will get in the output video? If the original clip is 16800 kbps, then the output being 16800 seems ok. If you edit the original clip then output a video file, then the maximum bitrate of 18000 might be used to render the edited parts? Just trying to learn.

Thanks,
Tommy

[Natal]

If you have smart render turned on it should not render your footage (other than a few frames at the start and end if cut/spliced) provided that your set bit rate is higher than your input bit rate.

Otherwise the footage will be re-rendered.

If you have applied effects or color correction, it will be re-rendered no matter what.

The problem is that the H.264 encoder used in VS is not very good, and will cause image degradation whenever there is rendering required. To minimize the effect of this, it is usually better than have a higher bit rate than what you started with if you want to minimize damage.

[lata]

Hi Natal

Thanks, yes I understand that, but when I choose to render using template that clearly uses 18000kbps why on earth does the new video show 16800kbps, as the original clip. Unless I edit the clip in which case 18000kbps is used.

Its not a problem for me, just an anomaly, I would use Same as First Video Clip, which is what the OP asked.

[Natal]

In the OP's case, his footage was originally 16800 kbps, so if smart render was active and he didn't edit the footage, then it would output as 16800 no matter what bit rate he selected as the maximum, provided it was over 16800. The reason is that no changes have been made to the original footage, so the average bit rate shouldn't change.

If he did something like color correction, for example, then everything would be re-rendered at the higher bit rate he selected.