noggin's posts, page 101

BBC World News | 30th October 2017 Onwards

That sounds like a standard OSD overlay then (rather than the full-screen UI).

Some cameras have two outputs (one with the OSD, one without the OSD) or a menu option to enable or disable the OSD on the external output. (If you are plugging in an external viewfinder you want the OSD, if you are plugging in the camera to an external link device, you probably don't)

Kodi Filmic Effect

MakeMKV shouldn't touch the video encoding or the audio encoding. If you are seeing a filmic effect on the output of MakeMKV, it's almost certainly caused by your playback solution not handling interlaced content correctly (not MakeMKV adding any artefacts.) MakeMKV literally just takes the video and audio streams from the DVD VOB files and puts them in a Matroska MKV wrapper - leaving the actual video and audio data untouched.

My suggested ffmpeg solution deinterlaces from native 25 interlaced frames (i25) per second (which has 50 fields per second motion) to 50 progressive frames (p50) (which preserves the 50 fields per second motion)

50p content removes deinterlacing limitations on your playback device (you've shifted the deinterlacing offline to ffmpeg) - and assuming your playback device is properly configured to output at 720p or 1080p 50Hz not 59.94/60Hz you will get nice smooth motion of native interlaced 576i25 content that has been converted to 576p60.

Also note that the command line I suggested is only using a constant bitrate for the audio (if you are happier with lower quality 192k or 128k audio - feel free to drop it).

For the libx264 video encoding it is using constant quality (-crf) not constant bitrate (-vb). A -crf of 18 is deemed close to visually lossless, a -crf of 23 is seen as pretty good. CRF encoding is a good compromise for speed vs quality - but you can switch to constant bitrate (replace the -crf value with -vb value e.g. -vb 4M for 4Mbs), or do variable bitrate two pass.

For two pass you still use "-vb" for the target average bitrate but then also add "-pass 1" for the first pass and "-pass 2" for the second pass. You can use "-an" rather than "-acodec aac -ab 256k" for the first pass to avoid time wasting by encoding the audio twice. The first pass is used by ffmpeg to analyse the entire video file, the second pass then uses this information to work out the optimum bitrate for each section of video based on this analysis. As a result you'll see a few log files generated by the first pass, which you shouldn't touch. You can also output the video for the first pass to a Null device rather than a file (as you don't need the video encode from the first pass) - but this varies depending on whether you are on a PC, Mac or Linux box.

BBC World News | 30th October 2017 Onwards

Do you mean the camera being used to cover Mariko went into a menu mode showing thumbnails of clips?

If so that's a result of the camcorder going into replay mode (to allow you to watch rushes you've already recorded, either for review or playout purposes). You see it happen occasionally on live feeds, but usually when the camera operator believes they are no longer on-air.

Brexit Dramarama

It wasn’t a ‘ban’, more of a reduction to much lower levels.

What capture devices are you using?

For info - the (ancient) Technisat Skystar 2 HD USB also (unusually) supports PLS/Multistream (though not ACM/VCM AIUI) By chance the chipset they used is compatible - which can be very useful for receiving the French and Italian DVB-T transmitter feeds that are on satellite.

I need to find some Linux support for that outside of TV Headend though (as I'd like to get MuMuDVB or DVBlast or TSDuck working with PLS stuff to create a UDP TS or similar - ideally to remodulate onto a DVB-T carrier)

TBS historically have had terrible official Linux driver support - and instead the CrazyCat media_build has often been better ISTR. Is the 5520SE well supported in Linux? If it is that combination of standards makes it quite compelling

** EDIT - looks like crazycat has worked on it - so definitely going to have a look **

EastEnders

Yes - I'd forgotten that major cock-up during the Corrie build.

Channel 4

Didn't C4 initially have their CA still at Horseferry Road, even though Playout had moved to Red Bee/Ericsson at the Broadcast Centre?

What capture devices are you using?

DVB-T2

HD HomeRun Dual Tuner (Ethernet)
Hauppauge WinTV-Dual HD, Pinnacle PCTV 290e, August T210 v1 (USB)
Raspberry Pi DVB-T2 Tuner uHAT. (SPI and I2C via Pi's GPIO)

DVB-S2

TBS Dual tuner PCI-E interface (can't remember the model - must be at least 8 years old)
Telestar Quad Tuner SAT>IP (Ethernet)
Techinsat Sky Star HD2 (USB)

They are running on a mix of platforms - some Windows, but most mainly Linux (mainly running TV Headend)

If you want a very cheap and neat DVB-T2 capture solution a Raspberry Pi Zero or 3A+ with the TV uHAT is a nice little project. (I'd use a cheap USB OTG Ethernet adaptor with the Zero for real-time viewing as the Zero W's WiFi is 2.4GHz 802.11n only and not great)

Kodi Filmic Effect

Yes - though outside the x86 PC arena, in the ARM SoC arena it isn't usually GPUs that handle video acceleration and deinterlacing, but a separate VPU (Video Processing Unit) block. (Though sometimes GPU blocks are used for some deinterlacing processes)


The Pi is slightly different because they are squeezing a lot of processing out of a small platform and the Broadcom Videocore SoC it is based on is effectively a GPU with an added ARM CPU, not an ARM SoC with an integrated GPU+VPU (the way the Pi boots is different to most ARM SoCs as a result).


1. The Pi comes as standard with h.264 decode and encode without a licence.

2. The Pi has optional MPEG-2 and VC-1 decode with paid for licences (£2.40 for MPEG2, £1.20 for VC-1 last time I checked)

3. Deinterlacing of h.264, MPEG-2, and VC-1 interlaced content is usually hardware accelerated using MMAL code (which runs in the GPU/VPU I believe. The balance of VPU/GPU grunt used for MMAL deinterlacing has changed over the years I believe (with some code moving to the GPU)

In the early days only the Quad Core Pi's (2B, and now 3B/3B+/3A+) could use MMAL advanced (roughly equivalent to YADIF 2x) deinterlacing for HD 1080i content, with the single core Pi's (Zeroes, original A/B, A+ and B+) only initially able to use MMAL Bob at 1080i.

Similarly the single core Pi's couldn't software decode MPEG2 - so you had to have the licence key to watch SD or HD MPEG2.

Now the 3-series models (and I think the 2B) have enough CPU power to software decode 576i SD MPEG2 (not sure about 1080i HD MPEG2) so the licence isn't required for basic Freeview SD and DVD viewing (and I think there is still power for SD MMAL Advanced de-interlacing too - though your power consumption and heat dissipation issues will increase)

For HD interlaced MPEG2 (US OTA TV, very early Blu-rays etc.) it is worth having the MPEG2 licence whatever model you have.



Well 720p60 has no deinterlacing - so that won't be an issue - but h.264 decoding with hardware acceleration (which is likely to be the dominant standard for any streaming service) is standard in all models of Pis - even the Zero.

The Pi has no full hardware VPU accelerated decode for h.265/HEVC encoded content - but a huge amount of work has gone into optimising h.265 decoding using CPU/GPU/VPU elements working together which means the Quad core Pis can handle 720p HEVC/h.265 streams and moderate bitrate 1080p24 stuff (though I think 1080p50 is pushing it, though may be possible with some overclocking)

More recent SoCs like the AMLogic S905/905X/905D/912, a lot of the Rockchips etc. have built in hardware VPU decode for h.265/HEVC stuff up to 4K (even the older S8xx series did 1080p HEVC/h.265)

EastEnders

One significant difference is that the Corrie build was a relocation - so the Corrie set was built on a new site on a large open space, which was the centre of a lot of building activity at the time.

The EastEnders build is taking place on a working broadcast site, in a residential area, with very limited access and a requirement for existing programmes made on that site to continue relatively undisturbed.

So there are differences that need to be taken into account when comparing the two.

How much did the Corrie relocation cost?

Interesting and unusual uses of teletext

If recordings survive it should be possible. The current VHS archaeology uses video cards with VBI capture for software decoding, not teletext decoders, and lots of clever processing and error comparison. The US version of WST is a modified version of the European one (with a lower data rate because of the reduce vision bandwidth of 6MHz System M transmission) so could be do-able. However the lack of source material is probably the barrier to anyone bothering to do this.

NOW TV

Has Virgin switched from HD MPEG2 to HD MPEG4/h.264 entirely now? (It was the odd one out in the UK as it launched HD services using previous-generation HD boxes that couldn't handle h.264 so had to use the far less efficient MPEG2 codec)