TVHeadend not using codec copy ?

STREIFF Antoine

Hey there,

I'm a little bit confused in here. So I've set up a tvheadend on a raspberry pi 4, because I need for my work to record a lot of tv programs. I appreciate TVheadend very much on an other installation, and so are my coworkers who also needs to use it and not a CLI only interface (that's relevant you'll see).

So when I'm using a simple ffmpeg command like this :

ffmpeg -err_detect ignore_err -i http://mystream -to 00:10:00 -codec copy /media/partage/dvr/test.mp4

my cpu usage goes to something like 1 or 2% percent. But when I'm trying to replicate that in tvheadend, the cpu goes to 400%, and clearly it's not the same behavior.

Here my stream configuration :

https://tof.cx/images/2020/04/02/989950efac55815df4d5306a45243df3.png

Here's the result with ffmpeg codec copy :

General Complete name : /Volumes/Share/dvr/test2.mp4 Format : MPEG-4 Format profile : Base Media Codec ID : isom (isom/iso2/avc1/mp41) File size : 58.3 MiB Duration : 3mn 20s Overall bit rate : 2 436 Kbps Writing application : Lavf58.20.100 Video ID : 1 Format : AVC Format/Info : Advanced Video Codec Format profile : Main@L3.1 Format settings : 2 Ref Frames Format settings, CABAC : No Format settings, ReFrames : 2 frames Format settings, GOP : M=3, N=50 Codec ID : avc1 Codec ID/Info : Advanced Video Coding Duration : 3mn 20s Bit rate : 2 300 Kbps Width : 1 280 pixels Height : 720 pixels Display aspect ratio : 16:9 Frame rate mode : Constant Frame rate : 25.000 fps Color space : YUV Chroma subsampling : 4:2:0 Bit depth : 8 bits Scan type : Progressive Bits/(Pixel*Frame) : 0.100 Stream size : 55.0 MiB (94%) Codec configuration box : avcC Audio ID : 2 Format : AAC LC Format/Info : Advanced Audio Codec Low Complexity Codec ID : mp4a-40-2 Duration : 3mn 20s Bit rate mode : Constant Bit rate : 128 Kbps Channel(s) : 1 channel Channel layout : C Sampling rate : 44.1 KHz Frame rate : 43.066 fps (1024 SPF) Compression mode : Lossy Stream size : 3.07 MiB (5%) Language : French Default : Yes Alternate group : 1

And the result with tvheadend :

General Complete name : /Volumes/Share/dvr/2020-04-01/BFMTV/Edition-speciale-BFMTV2020-04-0121-00.mp4 Format : MPEG-4 Format profile : Base Media Codec ID : isom (isom/iso2/avc1/iso6/mp41) File size : 8.40 MiB Duration : 42s 486ms Overall bit rate : 1 659 Kbps Movie name : Edition spéciale Writing application : Lavf58.20.100 Video ID : 1 Format : AVC Format/Info : Advanced Video Codec Format profile : High@L3.1 Format settings : CABAC / 4 Ref Frames Format settings, CABAC : Yes Format settings, ReFrames : 4 frames Codec ID : avc1 Codec ID/Info : Advanced Video Coding Duration : 40s 512ms Bit rate : 11.9 Kbps Nominal bit rate : 1 500 Kbps Width : 1 280 pixels Height : 720 pixels Display aspect ratio : 16:9 Frame rate mode : Variable Frame rate : 25.000 fps Minimum frame rate : 13.885 fps Maximum frame rate : 25.014 fps Color space : YUV Chroma subsampling : 4:2:0 Bit depth : 8 bits Scan type : Progressive Bits/(Pixel*Frame) : 0.001 Stream size : 58.6 KiB (1%) Writing library : x264 core 155 r2917 0a84d98 Encoding settings : cabac=1 / ref=3 / deblock=1:0:0 / analyse=0x3:0x113 / me=hex / subme=7 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=6 / lookahead_threads=1 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=2 / keyint=125 / keyint_min=12 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=abr / mbtree=1 / bitrate=1500 / ratetol=1.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / vbv_maxrate=1875 / vbv_bufsize=5625 / nal_hrd=none / filler=0 / ip_ratio=1.40 / aq=1:1.00 Codec configuration box : avcC Audio ID : 2 Format : AAC LC Format/Info : Advanced Audio Codec Low Complexity Codec ID : mp4a-40-2 Duration : 42s 486ms Bit rate mode : Constant Bit rate : 172 bps Nominal bit rate : 172 Kbps Channel(s) : 1 channel Channel layout : C Sampling rate : 48.0 KHz Frame rate : 46.875 fps (1024 SPF) Compression mode : Lossy Stream size : 915 Bytes (0%) Language : French Default : Yes Alternate group : 1

As you can see, Tvheadend is making a variable bitrate and variable framerate file, which is really bad for Premiere Pro (which is the main goal for all this).

My Pi4 is on Raspbian Buster, but I've also tried this with the same unfortunate result on libreelec.

Does anyone has any idea ?
<<

Saen Acro

You try to Trans-MUX or Trans-code?
Both are different.

STREIFF Antoine

Well it's pretty much transmuxing no ? I don't know I always thought transmuxing would imply a change of container and in that case it would be MP4 -> MP4, but I get your point.

So yeah, I absolutely want to avoid a transcode.

Saen Acro

UseMPEG-TS Spawn profile

STREIFF Antoine

Mmm I don't think I've got this one…

https://tof.cx/images/2020/04/02/0eca72fa003ca9e88c4ac81985cd7b1e.png

Should I try another build ?

STREIFF Antoine

Ok… so after a long day, I've managed to install 4.3 on a fresh Ubuntu on a rasp 4. But I've got a new problem. When I'm using this, it's working quite well :


 /usr/bin/ffmpeg -loglevel fatal -i pipe:0 -vcodec copy -acodec copy -metadata service_provider=STRING -metadata service_name=STRING -f mpegts -tune zerolatency pipe:1

But it's not the same as a ffmpeg -i pipe:0 -codec copy output.mp4 would work. the -f mpegts seems to add variable framerate, which is terrible for Premiere.
When I try


/usr/bin/ffmpeg -loglevel fatal -i pipe:0 -codec copy pipe:1

The file is created but stay at 0ko. The console show this :

-04-02 17:41:29.872 dvr: /media/partage/2020-04-02/_FR_-LA-CHAINE-METEO-FHD/L'__dition-du-soir.mp4 from adapter: "IPTV #2", network: "IPTV Automatic Network", mux: "blue.m3u - |FR| LA CHAINE METEO FHD", provider: "FFmpeg", service: "Service01" 2020-04-02 17:41:29.872 dvr: # type lang resolution aspect ratio sample rate channels 2020-04-02 17:41:29.872 dvr: 1 H264 ? ? 2020-04-02 17:41:29.872 dvr: 2 MPEG2AUDIO fre 96000 ? 2020-04-02 17:41:29.883 spawn: Executing "/usr/bin/ffmpeg"

Any idea ?

Saen Acro

Let's return on what is idea at beginning.
You want to record files or to restram in mp4 containr?

STREIFF Antoine

Well I want to record the files without any transcoding at all, and the best way to do that would be to replicate the -codec copy option of ffmpeg (which is not the case with -f mpegts . Maybe if I find the right option for my file ? Usually -f is quite optional…

edit : something strange, when I add -f mp4 , the file stay at 0ko... strange right ? But it is working with ffmpeg

Saen Acro

So record with regular pass profile,

else use post processing.

----

No need to make live harder because you can.

STREIFF Antoine

I think I found the answer.

So TvHeadend is using pipe:// , which is streaming. So, according to the ffmpeg doc, you can't use mp4 but TS and FLV. So basically I've made a post-record process : ffmpeg -i "%f" -map 0 -c copy /media/partage/dvr/%b
And that's doing the job, with 1 or 2% CPU usage

STREIFF Antoine

So I'm almost done with that setup ! Right now I've got two m3u and one dvb-t . The HD flux of the m3us are fine, but the fhd, 265 and dvbt streams are giving me variable framerates. It's mandatory for premiere to have constant framerate.

So I thought that my trick with -map 0 would do the job, but no.

So I was wondering : is there any way to force constant framerate through pipe:// ?

Saen Acro

Only with transcoding.