Digitize – Notes and Tips, Resolution, Bitrates, and such

 

Note: all references to ‘8 mm’ in texts and articles references below are referring to 8 mm Video , NOT 8mm Film, unless specifically clarified by J&P MLabs.

(1) Purpose

(2) Resolution

Table 2. A comparison of video quality between different formats Footnote3
Format Maximum Lines of Horizontal Resolution
VHS/VHS-C 240*
Betamax 250
8 mm 280
S-VHS/S-VHS-C 400
Laserdisc 425
Hi8 440
Digital 8 500
miniDV 520
Commercial DVD 540
Commercial Blu-ray 1080

*VHS tapes labeled with the letters HQ were slightly better in horizontal resolution at 250 lines.

 

(3) Bitrates

From Understanding bitrates in video files – help.encoding.com:

LD 240p 3G Mobile @ H.264 baseline profile 350 kbps (3 MB/minute)
LD 360p 4G Mobile @ H.264 main profile 700 kbps (6 MB/minute)
SD 480p WiFi @ H.264 main profile 1200 kbps (10 MB/minute)
HD 720p @ H.264 high profile 2500 kbps (20 MB/minute)
HD 1080p @ H.264 high profile 5000 kbps (35 MB/minute)

 

 

“The DVD resolution known as Half D1 (352×576 for PAL or 352×480 for NTSC) is a great choice for a source like VHS but the lessor resolution mentioned above (352×288 for PAL or 352×240 for NTSC) is a very low resolution for VHS and quality will definately suffer.

The “standard” DVD resolution is called Full D1 and is 720×576 for PAL or 720×480 for NTSC. The width is normally 720 but sometimes 704 is used and that is OK although it is more standard to use 720 for the width.”

..

“VHS can be better than 352×288. It is more like 320×576 for PAL.
I have tested this myself by capturing from miniDV and compared to a
capture of VHS recorded from the miniDV camera. The VHS capture
had full vertical resolution compared with the original.
And if you think about it, VHS can be interlaced so you will need
the full vertical resolution to keep the interlacing.

But if you are going to use 2 mbit/s then 352×288 may look better because this bitrate may not be enough with 352×576 resolution from a VHS source.”

 

Workflow

A pretty good graphic was found at The Digitization of VHS Videotapes – Technical Bulletin 31:

Workflow diagram for the conversion of VHS video to digital video

 

Extracts from Introduction to Digital Video Capturing, Recording TV – digitalfaq.com/guides/video/introduction-record-capture.htm:

Capture Software (Examples)

A capture card is only as good as the capture software. Remember to select a capture software does not harm the incoming signal, but rather encodes or transfers it as needed. Capture software often has the ability to both filters and re-encode the video to the desired codec or MPEG format. Much like capture cards, the quality of software varies greatly, from excellent to complete rubbish. Your goal is to use software that complements your card, in the pursuit of high quality video captures.

Capture software Pros Cons
ATI Multimedia Center (ATI MMC) Excellent quality video encodes, has a nice video clean-up filter called “VideoSoap”, free software designed explicitly to work with ATI cards. ATI MMC 7.7, 8.7 and 9.02 are the most stable versions. Only works with ATI cards, and even then, only well with “AIW” version cards. Can be difficult to install, uninstall or update.
VirtualDub Often referred to as the quintessential video capture tool. Is able to capture (and encode) video using any number of free filter plug-ins and codecs. Excellent tool, excellent quality. Free. Not the easiest tool to use, many options. Cannot capture MPEG natively, MPEG via codecs yields poor quality. Does not work with every card.
iuVCR Decent tool, works well with certain BT8x8 cards known for having sync trouble. Inversely, often known to cause sync errors on cards that otherwise act fine with VirtualVCR or VirtualDub. Limited resolution options. Can be crash-prone.
WinTV2000 Excellent quality video softare, works only with Hauppauge capture cards. Sort of like ATI MMC for Hauppauge. Only works well with the hardware MPEG encoder boards, not the cheap AVI cards.
VirtualVCR Free. Decent tool, works well with several cards. Tends to keep audio sync really well. Not as versatile and advanced as VirtualDub, does not work with every card.
Adobe Premiere Directly capture to the NLE timeline Limited options as compared to dedicated capture software, prone to crash
Final Cut Pro Directly capture to the NLE timeline Limited options as compared to dedicated capture software
Mediostream neoDVD Idiot-proof Expensive, mediocre quality, total lack of control over bit-rate and resolution, resulting in bloated files. A cheap all-in-one direct-to-DVD capture tool.
Intervideo WinDVD Recorder, WinDVR None Forces a blended de-interlace on all captures, blocky quality, any resolution below 720×480 is almost all macroblocks. Few options, in terms of settings (bitrate, res, audio, etc).
Cyberlink PowerVCR Though it comes default with a forced blend deinterlace, it can be hacked to allow interlaced MPEG captures and add resolutions. Has a handful of basic video/audio options Not super-high-quality MPEG encodes, about on par with WinDVR, requires hacks to work decent, only really works well at 720×480 res. Has chronic issues with dropped video frames (not reported) which leads to audio sync errors.
MainConcept 1.4 Essentially the MPEG Encoder software in a capture mode, therefore has many options Expensive, optimized for PAL, not NTSC. Quality of encodes is not always excellent. Will only drop video and not audio frames, causing sound sync errors. EXTREMELY DEMANDING on the CPU, even newer 2.0-3.0Ghz systems can have problems.
MainConcept PVR None. Different from the MC 1.4 encoder. Total trash. Crashes all the time, barely works. Beta-quality software that should have never left R&D. MainConcept tech support is totally worthless.
Snapstream, Showshifter, BeyondTV, SageTV, GB-PVR, etc PVR software, not really capture software. Works fine for turning a computer into a VCR with timer record functions. Not the highest quality encoding, buggy, difficult to setup, and often works with only a few cards. For the purpose of this guide, these are not suitable software.
Anything not listed here Search google.com or videohelp.com for reviews on the software in question. Anything not on this list is typically not listed for a purpose, often because the software is an all-in-one solution, low quality, or dedicated to a certain piece of hardware.

 

What is the Source? And What Capture Resolution?

The Understanding Your Source capture guide has detailed information on source files. However, the following quick-list will cover the suggested capture resolutions for the most common sources, sorted by resolution:

  • 352×480 = VHS, S-VHS, 8mm, Hi8, Betamax, most of satellite, cable, broadcast antenna
  • 480×480 = anything being converted directly to SVCD
  • 640×480 = anything being captured as AVI intended for advanced editing in an NLE
  • 704×480 = laserdiscs, Betacam SP, PPV satellite channels
  • 720×480 = laserdiscs, Betacam SP, PPV satellite channels

Suggested AVI capture resolution. If you plan to heavily edit to video, experience has shown capturing at 640×480 or 720×480 resolution will often yield the best final product. It may be a huge file, but if quality is important, you’ll find a way to store it. You can resize to a smaller resolution when encoding the final MPEG.

 

MPEG or AVI?

All too often, videographers and hobbyists make this appear to be a harder choice than it really is. Choosing AVI over MPEG, or MPEG over AVI, is a simple choice to make, and should take maybe 10 seconds to decide.

Ask yourself this one question: Do you plan to do advanced editing* with the video?

  • If yes, then use an uncompressed (YUY2) or low compression (HuffYUV or MJPEG) codec using the AVI file format. Use this AVI to edit in your favorite editing program (like Adobe Premiere) and then encode to MPEG-2 (for DVD) or other desired final format.
  • If no, and you merely want to convert the video to VCD or DVD format, then encode directly to MPEG-1 or MPEG-2. You gain no benefits** by capturing AVI then encoding to MPEG afterwards. In fact, all it does is take more time.

* Removing commercials and cutting away unwanted footage is NOT considered advanced editing. That is basic cutting and splicing of footage. You can do this with either AVI or MPEG without reconverting the video or harming quality.
** Capturing in MPEG format assumes you have a decent MPEG capture card and capture program, such as an ATI All In Wonder card using ATI MMC. Many cards and many software give poor MPEG capture results. Non-ATI users can try other programs, but the options are few and disappointing. This is the main reason I suggest ATI cards. Cards like Matrox, Canopus and Hauppauge can also give great results, using their supplied software.

Note: Capturing in high compression codecs, like that of XviD/Divx MPEG-4, H.264 MPEG-4 or Windows Media, is not suggested. It will give lower quality video output using that method. For best results, capture with an uncompressed or low-compression codec, and then re-encode the material to the higher compression ratio.

 

 

Extracts from Guide to Understanding Video Sources, Part 2 – Capturing Videotapes – digitalfaq.com/guides/video/capture-understand-sources.htm:

Analog Source Resolutions

There are only two kinds of source: analog and digital. Analog source comes from tapes or analog broadcast signals, and digital source comes from computers, digital broadcast signals or digital cameras. Analog source cannot be measured in the same terminology as digital source. While resolutions, bit-rates, audio levels, etc, are rigid measurements in the digital world, this does not hold true in the analog world. Analog sources are measured differently, typically using various power and output measurements. The following table uses approximate digital equivalents for the various analog sources. The table presents both IN PRACTICE and IN THEORY numbers for the digital equivalents, with theory being the higher of the two. Information presented on this chart currently reflects only the USA NTSC video standard. PAL and SECAM standards (outside the USA) may be added with a future updates. In most cases, you can simply substitute x480 with x576 and get the PAL variants.

Format: Analog Measurement: Digital Equivalent: Audio and Other Info: Suggested Capture Size:
Broadcast antenna television and analog cable Up to 4.2 MHz, drop-frame 60hz power cycle, 300-340 lines of resolution, interlaced 350×480 to 400×480 interlaced 29.97fps NTSC, audio approximately 44.1kHz, 4:2:2 sampling 352×480
Satellite (DSS,DVB) and digital cable Interlaced digital signal, encrypted 352×480, 412×480, 480×480, 544×480, 640×480, 704×480, 720×480, and many others. Depends on provider and channel 29.97fps NTSC, audio can be MPEG audio or Dolby AC3 audio, often at 44.1kHz, 4:2:0 and 4:2:2 sampling 352×480 or 704×480 or 720×480
VHS Up to 3.0 Mhz (very weak), 240 lines of resolution, interlaced 250×480 to 300×480 interlaced 29.97fps NTSC, HiFi audio about 44.1kHz, 4:2:2 sampling 352×480
Super VHS (S-VHS) Up to 5.0 Mhz (very strong), 400-425 lines of resolution, interlaced 400×480 to 500×480 interlaced 29.97fps NTSC, HiFi audio about 44.1kHz kHz, requires S-VHS player or SQPB, 4:2:2 sampling 352×480 or 704×480 or 720×480
Super VHS ET  (S-VHS-ET) Between VHS and S-VHS measurements, interlaced Between 250×480 and 500×480, normally 350×480 Same as S-VHS, use high grade VHS tapes only, 4:2:2 sampling 352×480
Betamax 250 lines of resolution, interlaced Similar to VHS This is not the same as Betacam SP, 4:2:2 sampling 352×480
Betacam SP Up to 7.5 Mhz, 360 lines of resolution 400×480 to 500×480, interlaced High bandwidth used for color retention and saturation 704×480 or 720×480
8mm Similar to VHS, interlaced 270×480 to 300×480 29.97fps NTSC, 4:2:2 sampling 352×480
Hi8 Similar to S-VHS, interlaced Similar to S-VHS 29.97fps NTSC, 4:2:2 sampling 704×480 or 720×480
Digital 8 Interlaced digital DV signal DV 720×480 This is digital data on an analog tape, 4:1:1 or 4:2:0 DV sampling N/A DV 720×480
Laserdisc Up to 5.0 Mhz, 400-425 lines of resolution, interlaced 528×480 and 544×480 Analog video on a digital media. Audio can be stored in an analog track or in a digital track (Dolby AC3, DTS). 29.97fps NTSC, 4:2:2 sampling 704×480 or 720×480

Analog Source Notes:

 

  • Digital cable: Not all digital cable is a digital signal. Sometime it is a digitally-compressed analog signals being decompressed by the digital cable box. Check with your cable provider to see what you have. Although satellite systems are digital signals, encryption prevents them from being downloaded. The only way to legally record digital satellite is by using analog methods. Satellite is either on or off, and cannot be harmed by static or other noises that affect cable or broadcast. DirecTV and DISH Network typically use 544×480 and 480×480 resolutions.
  • VHS/S-VHS History: The Video Home System (VHS) format was invented by Victor Company of Japan (JVC) in 1976. Super VHS (S-VHS) format is a 1987 JVC invention that made use of s-video (“separated-video” cable that separates luma from chroma) and incorporated a denser particle mixture on the tapes.
  • S-VHS-ET and SQPB: Although some VHS units allow SQPB (S-VHS quasi-playback), it is still a VHS-quality signal being broadcast from a VHS player. VHS VCRs are unable to extract all the S-VHS information, so use an S-VHS player for S-VHS tapes. S-VHS-ET is the official name given to an old cheap trick used by many poor or cheapskate S-VHS users. In the old days, we would drill or burn holes in a VHS cassette housing, as S-VHS tapes have holes that VHS tapes do not, thus allowing players to know the difference in the equal-size tapes. In the past few years, JVC labeled it S-VHS Extended Timebase (ET mode) and has put the option onto its recorders. A VHS tape actually has more signal bandwidth available than is used by VHS players. However, it is not quite as good as a regular S-VHS tape. I highly suggest JVC, TDK EHG or any broadcast-quality VHS tape for S-VHS-ET use.
  • Satellite TV: Satellite television is a special format (DVB/DSS) of MPEG-2. Satellite centers (like the DirecTV location in Colorado, or the DISH centers in Wyoming and Arizona) encode the video to MPEG-2, uplink it to a satellite, and it is then resent to Earth and intercepted by the digital dishes on our roof. Because the original digital files cannot be accessed (due to encryption), footage must be captured from the analog output given off by the satellite receivers, and this is why “digital” satellite has been included in this analog source list. It is often higher quality than cable or broadcast because it is a digital signal, and cannot be harmed by static or other noise than affects cable and broadcast, and therefore appears cleaner and crisper. Satellite signals are either on or off (excluding macroblocking and freezing due to signal interferences as caused by weather or aerial objects). Some DVB and FTA signals can be captured directly with acquisition cards (not really capture, more like downloading data). This is because the information is not encrypted. More information on digital satellite broadcasts can be found at CoolSTF.com and Henry-Davis.com.

Digital Source Resolutions

Digital source is already digital. It has rigid limits, specifications of acceptability, and resolutions and bit-rate. Everything about a digital file can be quantified and qualified, unlike analog. Digital formats like VCD and DVD must adhere to certain specifications. This chart is completely technical, contains all information about the spec. Newbies may not understand all of this information just quite yet, but it will be important to refer back to when capturing, encoding and authoring.

This information appears in this “understanding your source” guide mainly for comparisons purpose to the analog chart above, as well as for those that desire to edit or re-convert video already in the digital domain.

Video format File Format Resolutions Video bit-rates Audio specs
DVD-Video NTSC (4:3): 352×240, 352×480, 704×480, 720×480, NTSC (16:9 widescreen): 704×480, 720×480,PAL (4:3), 352×288, 352×576, 704×576, 720×576,PAL (16:9 widescreen): 704×576, 720×576 Up to 10.08Mb/s total combined bitrate. Up to 9.8Mb/s max video bit-rate. CBR, CVBR, or VBR (1) AC3 Dolby Digital stereo or surround. Average AC3 stereo is 192-384k. Average surround is 448k or higher. (2) LPCM uncompressed 1536k WAV/AIFF. (3) DTS, same bit-rate as AC3.,(4) MPEG Layer II (MP2) stereo, 192-256k bit-rate, not officially supported in the spec
DVD-Video MPEG-1, sequence headers at each GOP, 4:2:0,
MP@ML
NTSC (4:3): 352×240, PAL (4:3): 352×288 Between 1.150Mb/s and 1.856Mb/s CBR video
bitrate
Same audio spec as MPEG-2 version
VideoCD (VCD) MPEG-1 (4:2:0) NTSC (4:3): 352×240, PAL (4:3): 352×288 Exactly 1.150Mb/s CBR total video/audio
bit-rate
Exactly 224k MPEG Layer II (MP2) audio
Super VideoCD (SVCD), Chaoji VCD, China Video Disc (CVD) MPEG-2 (4:2:0) NTSC: (4:3) 480×480, PAL (4:3): 480×576, CVD uses 352×480 or 352×576 resolution variant Up to 2.520Mb/s VBR max, total combined video/audio
bit-rate
Exactly 224k MPEG Layer II (MP2) audio
XVCD MPEG-1 or MPEG-2, not an official “standard” Any, standard disc and DVB/VR resolutions suggested Any, but max 2.520Mb/s is suggested, usually VBR Any, MP2 suggested
MiniDV, DV25, consumer DV DV25 codec AVI, 4:1:1 (USA) or 4:2:0 (PAL) NTSC (4:3): 720×480, PAL (4:3): 720×576 25Mb/s combined audio/video (5:1 compression) LPCM 1536k uncompressed audio
MPEG-4, XVID, DIVX FourCC AVI codecs, often used to share files
online
Varies, but standard resolutions includes 640×480 and 512×384 for 4:3 content Varies Typically AC3, OGG, MP3 and MP2, stereo or
mono
Other formats Digital video has an near-infinite amount of bit-rate, resolution and format combinations. Other formats include RealMedia, QuickTime and Windows Media Video (WMV). Depends on the format Depends on the format Depends on the format. Many formats have dedicated audio streams.

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