Why not capture analog video/audio both lossless?

[hajes29a]

I always captured analogue video in huffyuv/yuv + pcm from VHS.

Is there any reason why not compress audio lossless with FLAC on the fly, please?

a/v sync issues?

[mbassiouny]

With the same line of reasoning, one could wonder why not use x264 with crf =0(lossless) for capturing

Here is my reason, there might be other reasons I do not know of:

The goal when capturing is to use the lightest codec possible with the least load on the CPU. FLAC is a bit more CPU-intensive.

What will happen if your CPU is too overloaded while capturing is that you are going to drop frames. Something you do not want. My guess is with reasonably modern CPUs (like i5/i7 3rd gen or higher) doing FLAC encoding on the fly is probably manageable.

[lordsmurf]

FLAC is likely too resource intensive for realtime compression. Remember, it's per-core speeds that matter in capturing, not the number of cores in modern processors. Core speeds haven't budged much in the past decade, we just added more.

There's also interleave to consider, they relationship between the audio and video. Offhand, I don't believe FLAC can be containerized with video (MKV, MP4, AVI, etc) in this way. FLAC was intended purely for audio, as separate lossless streams.

Audio is somewhat tiny anyway, even uncompressed PCM. No real reason to do it.

[dpalomaki]

FWIW: Considering that audio is a small percentage of the total data stream, video being much greater. IMO in this day of low cost storage the strikes me as being little benefit to compressing audio when capturing. Audio compression can be reserved for the ultimate distribution format as appropriate. One less codec to manage.

[hajes29a]

Thanks guys for reply

x264 was never intended for edit, cannot capture in plain YUV if I recall.

I doubt Ryzen 9 5950X @ 4.1GHz would be issue or Xeon E5-2697v2 in my computing rig. We used to do it on Athlons, Pentiums guys...I am sure smartphone can do it if one can install capture card )

I see your point. I never had issues with old, proven, mature, and "obsolete" tech. Despite I hate it in my SounDevices MixPre recorder...BWF uncompressed WAV 32b float @96kHz is not much fun if you record 1TB data over a week in wilderness.

"Waste of cheap space" strategy...that is exactly how you end up with 1PiB server :-P In my best days of photography, I brought 256GB of RAW photos per week.

For RAW video edit HDD cold storage is crap... SSD tech still costs 100TB cca 50k$. Even copy over 10Gb-eth is annoying.

Every two years, I had to upgrade server ROFL while audio is tiny, like 600MB per hour...1000 hours is 600GB...i like to upgrade my storage every 5years nowadays )

[latreche34]

Both lossless audio (such as PCM) and compressed audio (such as AAC) can be used, However audio format compatibility with playback devices is very important here, Most devices cannot playback videos with unusual audio formats, or formats that are anything other than 48KHz/16bit. So you have to know what's your playback target, Online file sharing, flash media, offline server playback, physical media formats, also what devices are going to playback those videos, TV, smart device, media player... etc.

Here is a nice write up about some audio formats for video.

[hajes29a]

As mentioned above by "compatibility issues" is main problem as I have already experienced with legendary VirtualDub2/AVIsynth on Win10. Might be also problem with Win10 that causes to fail. AVIsynth script fed RAW video huffyuv/PCM, filtering, VirtualDub2 compress huffyuv, and transcode audio to FLAC.

It came out ready for Thrash...video ok, audio noises similar to alien language.

BOTTOM LINE is K.I.S.S as usually

Win huffyuv + PCM
Linux ffv1 + PCM

live happily ever after

[hodgey]

FLAC audio is supported in MKV files so it's possible if you capture with ffmpeg (and you intend to use it with another ffmpeg-based application) - it won't work in .avi files though as those are more limited in what audio formats are supported so best to just use PCM there.

For long term archival purposes flac+ffv1 in .mkv will give you some slight space saving over just leaving the audio as PCM if you need it.

[latreche34]

For non music tapes, such as documentary and dialog, I use AAC @ 192Kbps, 16/48 works like a charm on every device I have tested.

[hajes29a]

Quote:

Originally Posted by hodgey

For long term archival purposes flac+ffv1 in .mkv will give you some slight space saving over just leaving the audio as PCM if you need it.

I have recently read about Swiss archival studio working for gov institution. They push with other studios some standards. They use mentioned ffmpeg > ffv1/flac/mkv combo as OpenSource standard for archival purpose.

They do not share what they do with tapes. Since they are sponsored from our tax money, they may have some studio-grade HW. They also push some archive industry standard with RAWcooked

As hobby, I have already "wasted" at least 10k $ in analogue/digital photography, video is next step. I would like to get some full-frame TBC for max quality. This ancient stuff is hard to get in Europe. VCRshop guys have some, but it is something that Maria Theresia used.

Suggested TBC by lordsmurf are nowhere in Europe....or I didn't find anything yet. All European pro studios claim professional grade analogue/digital conversion...all they do is decent S-VHS deck + Grass valley AVDC 110/300 combo while preaching about poor hobby guys like us, and their "best" RAW video quality.

It is either pure skull poverty/ignorance, or they just exploit the ignorance of normies. I have already done better captures with tourist gear than these "experts". I decided to "waste" another 1k $ to get it done correctly because you will pay same price for poor capture.

[dpalomaki]

It boils down to a few questions.

What formats will be supported over the life of the captured video. If the files will be discarded when you are off the scene that may be a different answer than if you want them read 200 years from now. Also you may need to provide a legacy playback capability, or provide for media conversion over time as things age out. Think 8-track tapes as an example. Look at the history of innovative (at the time) media formats that have died. Sony's MiniDisc anyone? However it is still relatively to setup to play (and clean up) 78 rpm records.

Who is the ultimate customer, now and in the foreseeable future? Will your approach meet their expectations? Will the future customer have the technical expertise needed to use the recorded material?

How much time and energy (and $$$) are you willing to invest in the process?

As an aside: my observation is that few people care about their wedding videos a few years into the future, especially if a divorce is involved.

[hajes29a]

I am not worried about future because we are currently at brink of extinction so anything intangible, such as digital world, will be pointless :-D Look at crypto mania...we build it, I like the idea, but where you pay for RentalWoman with crypto while in global conflict? There will be no electricity, and as usually, barbaric relics will rule the Earth ;-)

Where do you play with fancy electronic, without own generator. How do you connect to Internet? Post-apocalyptic kids cannot even live without Internet. Such archival worries do not bother me much ;-)

Microsoft works on some glass-based cold storage. As once asked by some great artist - what legacy brings the 1900-2000+ generations...art is dead, humanoids suffer from raging skull poverty. As normal mortal - without A-bomb bunker where you can store all the old-school stuff - why worry about future ;-)

if we survive by some miracle, there will always be another formats.

I keep analogue film from my MF camera. Doesn't exist digital tech capable to store all light...PERIOD...don't get me started with reproduction of digital. I have 20+ old footages that still work huffyuv/PCM. As long as Open Source will work, I have no worries about Open Source formats. They will always be here.

If you worry, transcode. I move my archives every 5 years. There is always new tech, larger, faster.

[latreche34]

In Europe you should be looking for Snell & Wilcox devices, They are not just TBCs, they are analog to digital converters with SDI out, The idea of TBC started back in the day when people were doing tape dubs and video editing from one deck to another, That analog workflow is used with consumer capture devices, Big buck archiving business use studio grade A/D converters. S&W managed to get their boxes to half rack size using FPGA in the Kudos+ model series vs the old pizza box proprietary designs.

Look for TBS models, and note that S&W was later on acquired by Grass Valley and they kept the same design but changed model numbering to CRV, Here are some manuals:

TBS800 CRV600
There are more than 8 models I believe based on output options for audio, Some have firewire for DV which is not needed.

[hajes29a]

Thanks chief. I am betting that is not 500€ toy, even the old ones.

-- merged --

I have found one SW CVR-600AD. There is some weird audio 4pin input.

Do I need to run audio via video sync as well or can I bypass it, and connect directly to capture card, please?

[lordsmurf]

Quote:

Originally Posted by hajes29a

All European pro studios claim professional grade analogue/digital conversion...all they do is decent S-VHS deck + Grass valley AVDC 110/300 combo while preaching about poor hobby guys like us, and their "best" RAW video quality.
It is either pure skull poverty/ignorance, or they just exploit the ignorance of normies. I have already done better captures with tourist gear than these "experts". I decided to "waste" another 1k $ to get it done correctly because you will pay same price for poor capture.

Sadly, many are just dumb newbies themselves. Simply by visiting this site, and reading, you now know more than they do.

[hajes29a]

Quote:

Originally Posted by lordsmurf

Sadly, many are just dumb newbies themselves. Simply by visiting this site, and reading, you now know more than they do.

They do it for money, not for themselves, not for quality because they know most people have no idea (including themselves...before I gained more wealth, I wasn't aware of some common analogue issues as well...I see now in my 20+y old captures, how crap they are).

They buy Grass Valley ADVC110/300, and claim "professional" gear. If you do something for money, there is no wealth involved. You are still poor, earning paper from clueless.

They do some "AI" denoise/deinterlace, compress to MPEG2...that's all folks. Unless, it looks really crap, and the customer still has tourist VCR player from Julius Caesar era...they see no difference. You can be proud, or rich ;-)

We have built Internet many years ago, and modern people are so lazy/ignorant to even read. Some at least think, and see, that 200$ "pro" digitalising is the same as buying the ADVC series themselves. Because some smart modern kids, can do what they inherited from us "pioneers"...Handbrake and similar monkey SWs are the simplest solution if people do some digging first

Common price in Swiss is 40CHF/40$ per hour. Everybody has got at least 4 VHS tapes from past. ADVC is "perfect" solution.

I am for max. amateur quality for reasonable price. I already "wasted" 1000$ on gear, it achieves perhaps 90% of broadcast/studio quality...chasing the remaining 10% is a very expensive hobby. I hoped to meet someone from Europe who already has all this gear, and can digitalise. No luck so far.

It would be the easiest solution, but I do not learn anything ;-) In third wave of my 20+ years digitalising career, I still find gaps in knowledge.

[Eric-Jan]

Strange, i allways thought compression during capture, makes that data can be written faster to storage, and uncompressed data during capture is greater in volume, so it will hold up storage onto the storage volume, hence dropped frames...

[mbassiouny]

Quote:

makes that data can be written faster to storage,

Write faster to storage: yes, compute faster on CPU: No.

Dropped frames can happen whenever there is a bottleneck, CPU, hard drive writing speed, or even sth else. It does not matter which.

[hajes29a]

I doubt there are still bottlenecks in modern computing ;-)

CPU idling ~10%
SSD/SATA 300-500MBs sustainable write
SSD/NVMe 1000-1500MBs
DDR4 50GBs?
Even RAMdisk manages at least 1GBs

Of course, if someone uses old rig I understand.

As already written - major issue will be compatibility.

I have tried h264 lossless, it hogs cpu - it cannot be opened in DaVinci Resolve. FLAC not bad, I guess same issue as h264

[lordsmurf]

Quote:

Originally Posted by hajes29a

I doubt there are still bottlenecks in modern computing ;-)

You would be wrong. Analog video conversion still operates in a per-core world. Having multi-core CPUs simply does not matter. So in terms of CPU overhead, look at core speed, not # of cores. Almost all CPU gains in the past decade were just x86 adding cores, not really meaningfully improving speeds of cores.

Quote:

CPU idling ~10%

Look closer at that measure. It's for all cores. Drill down.

Quote:

SSD/SATA 300-500MBs sustainable write
SSD/NVMe 1000-1500MBs

Does not matter. The fragmented nature of SSD can actually cause drops. It fully depends on the 'LC and the caching of drives. Many drives waiver in throughput (not truly sustained), and a dip in realtime write, therefore drops frames. Drive fill becomes more important here.

Quote:

DDR4 50GBs?
Even RAMdisk manages at least 1GBs

RAM does not matter at all for capturing, aside from support the base needs of the software. Capturing is almost entirely I/O and CPU

Quote:

Of course, if someone uses old rig I understand.

"Old" has nothing to do with it. In fact, "new" rigs tend to give more issues than not. That's because modern computing was not part of the considerations of capture at the time, the 00s. This is why random computers can give random results.