Pal dv

[Anakunda]

Hello,

can I use this format by Sony Vegas to save video loss?
IE. is it lossless?
What is the difference between DV and uncompressed?

If not, what software can I use to trim two MPEG2 parts, then join them to MPEG2 without reencoding? I've tried Womble MPEG Wizard but doesnot seem it doesnot reencode..

Thanks for any ideas.

[Emulgator]

DV is not lossless. It was conceived as an end-user format.
DV uses DCT, as JPEG does. YCbCr (as JPEG does). Bitrate 25Mbps.
Further restrictions:
Unlike JPEG (4:4:4) Colour subsampling is 4:2:0 for PAL, 4:1:1 for NTSC.
Noisy and complex motion will exhibit blockiness, encoder/decoder dependent.
Every generation (decompression/recompression) will lose quality.
I have made some frame comparisons in EditStudio on noisy footage.
Even DV decoder dependent alone there were visible differences.

Digibeta (conceived as a professional format)
is related to DV like a big brother but applies less compression,
gives more bitrate: 90Mbps, 4:2:2 subsampling and so is more transparent.
Wikipedia has more.

BTW, I have tried and used different formats as intermediate,
trying and in consequence dropping for hm, lossy reasons:

Largarith (loses dark and grainy details),
Canopus HQ (LL would be okay, but there are incompatibilities,
Huffyuv (always version conflicts with the misery ffdshow HFYU),
The Original HFYU is ok, but I am tired to countercheck which HFYU had been used
and finally find out that the poorer version had been called...

In the end I rather will afford the higher bitrate, instead of ending up with a mediocre result.
Now I am back to: Plain YUV Uncompressed. This is lossless and accepted everywhere.

MPEG2: If you need to trim at I-Frames, reencoding isn't necessary.
MPEG2: Trim and join: Cuttermaran, MPEG2Schnitt.
If you need to trim and join at B-Frames, reencoding is a must.
VideoReDo, Womble.

[Anakunda]

thanks much, this explains all.
I just wonder there's no video lossless compression. I would appreciate it.

[Ghitulescu]

There is , you simply don't have the space for it ;)

[Emulgator]

Yes, and compression and lossless do still look strange to me when married.
But it is said to be there.
x264 has a lossless mode which is reported to be useful as intermediate or mezzanine format for archival.
Haven't tried it yet, but soon will...

[Anakunda]

I have installed x264vfw now so it was possible to save losslessly as avi, but the rendered video looks apparently less contrastly and also considerably brighter compared to the original even if I used best output. Anybody knows why? How do I force Vegas to obey the original image tone params

[Emulgator]

Workflow please. Samples.
Source format as reported by mediainfo,
Vegas settings.
Colourspace RGB lossless or YUV lossless ?
There may be the difference.
Which frameserver if used (debugmode etc.)
x264 in .avi ?
Final format as reported by mediainfo.

[Anakunda]

I'm back to the project.

I attach 2 screen shots: 1st from original video. this is mpeg. 2nd from Vegas render output (x264 crf 22):

http://img825.imageshack.us/img825/9144/originalpiture.png
http://img580.imageshack.us/img580/9216/vegaspicture.png

although vegas has a more green tone that's ok as I changed color balance slightly, the picture from vegas is more pale, or less contrast (independent on color balance).

Here's video properties from within Vegas:
http://img830.imageshack.us/img830/8059/videoprops.png

and media info of original and rendered video:

General
Format : MPEG-PS
File size : 766 MiB
Duration : 29mn 48s
Overall bit rate : 3 594 Kbps

Video
ID : 224 (0xE0)
Format : MPEG Video
Format version : Version 2
Format profile : Main@Main
Format settings, BVOP : Yes
Format settings, Matrix : Default
Format settings, GOP : M=3, N=12
Duration : 29mn 48s
Bit rate mode : Variable
Bit rate : 3 331 Kbps
Nominal bit rate : 15.0 Mbps
Width : 720 pixels
Height : 576 pixels
Display aspect ratio : 16:9
Frame rate : 25.000 fps
Standard : PAL
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Interlaced
Scan order : Top Field First
Bits/(Pixel*Frame) : 0.321
Stream size : 710 MiB (93%)

Audio
ID : 192 (0xC0)
Format : MPEG Audio
Format version : Version 1
Format profile : Layer 2
Duration : 29mn 48s
Bit rate mode : Constant
Bit rate : 192 Kbps
Channel(s) : 2 channels
Sampling rate : 48.0 KHz
Video delay : -185ms
Stream size : 40.9 MiB (5%)

General
Format : AVI
Format/Info : Audio Video Interleave
File size : 222 MiB
Duration : 28mn 26s
Overall bit rate : 1 094 Kbps
TCOD : 0
TCDO : 17060400000

Video
ID : 0
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.0
Format settings, CABAC : Yes
Format settings, ReFrames : 16 frames
Codec ID : H264
Duration : 28mn 26s
Bit rate : 1 035 Kbps
Width : 720 pixels
Height : 576 pixels
Display aspect ratio : 1.172
Frame rate : 25.000 fps
Standard : PAL
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.100
Stream size : 211 MiB (95%)
Writing library : x264 core 104 r1713bm c276662
Encoding settings : cabac=1 / ref=16 / deblock=1:-1:-1 / analyse=0x3:0x133 / me=umh / subme=10 / psy=1 / psy_rd=1.00:0.15 / mixed_ref=1 / me_range=24 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-3 / threads=3 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / constrained_intra=0 / bframes=8 / b_pyramid=2 / b_adapt=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=60 / rc=crf / mbtree=1 / crf=22.0 / qcomp=0.60 / qpmin=10 / qpmax=51 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00


And rendering preferences:
http://img832.imageshack.us/img832/6194/prefs1.png
http://img815.imageshack.us/img815/2024/prefs2.png