Question / Help OBS Local Recording, Other Video Clips for Assembly and FFMPEG Merge

[tommythewoo]

Hello there,

I seem to be falling down a re-encoding hole here and think it best to ask for help as I could use some light on my situation.

The ultimate goal is to try to maximize the Merge function of FFMPEG by pre-encoding content in a final format to concatenate with like clips.

The structure of the video is this; Logo Sting, Short Opener, OBS Recording.

The final target is a YouTube H264 HQ preset used in myFFMPEG and is as follows:

General
Complete name : Z:\VH7T0K~L\PNA1X9~C\04D306~9\OLR7T2~4\219TCZ~V.MP4
Format : MPEG-4
Format profile : Base Media
Codec ID : isom (isom/iso2/avc1/mp41)
File size : 10.8 MiB
Duration : 12 s 32 ms
Overall bit rate mode : Variable
Overall bit rate : 7 541 kb/s
Writing application : Lavf58.25.100

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : Main@L5.1
Format settings, CABAC : Yes
Format settings, ReFrames : 3 frames
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 12 s 0 ms
Bit rate : 7 260 kb/s
Width : 2 560 pixels
Height : 1 440 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 60.000 FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.033
Stream size : 10.4 MiB (96%)
Writing library : x264 core 157 r2935 545de2f
Encoding settings : cabac=1 / ref=3 / deblock=1:0:0 / analyse=0x1:0x130 / me=hex / subme=7 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=0 / cqm=0 / deadzone=0,0 / 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=1 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=1 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=crf / mbtree=1 / crf=20.0 / qcomp=0.60 / qpmin=3 / qpmax=51 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00
Language : English

Audio
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : 40
Duration : 12 s 32 ms
Bit rate mode : Variable
Bit rate : 288 kb/s
Maximum bit rate : 317 kb/s
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 spf)
Compression mode : Lossy
Stream size : 421 KiB (4%)
Language : English
Default : Yes
Alternate group : 1

I keep thinking that this process was more so found by guesswork and that I am missing something or that there can be a more effective way to approach merging clips rather than rendering the all the clips, in one timeline as an final piece.

Any insight would be helpful, thanks for reading through.

Twoo

 

[R1CH]

Use the ffmpeg concat option: https://trac.ffmpeg.org/wiki/Concatenate

Assuming all your videos are encoded the same (width, height, encoder, FPS, etc) they should be joinable in this way.

 

[tommythewoo]

Sweet, thank you Rich. Is Concatenate different than Merge, same thing??

Hmm, reading some more, Concact does not require the same codec or same codec properties.

If I could clarify, a Codec lives in a Container; H.264 lives inside MP4 container? I feel silly asking as I should know this by now...

Thanks again for the response, it has been helpful already. :)

Twoo

 

[R1CH]

A container is a format like MOV, MKV, MP4, AVI etc. A container can contain multiple different "streams", eg video and audio, subtitles, chapter data, etc.

A video stream is a certain format (eg H264), and can be encoded by multiple compatible codecs (eg x264, NVENC, AMF).

Your typical MP4 container will be housing an H264 video stream and an AAC audio stream. As long as both the video and audio streams were encoded with the same codec and parameters, they can be pulled out of the container, joined together and put back in without any quality loss.

I generally work with MKV as it supports almost all formats, then turn to MP4 at the very final stage.

 

[tommythewoo]

Well, that cleared things up a bit. Thank you very much for that.

Can you just elaborate as to why MKV is more flexible that say MP4, it seems there is more designation with MKV

Also, it seems this may lead to using MKV, what settings would you adjust for maximum quality output for a recording to be Concatenated and uploaded to YouTube. Any values recommended for settings of OBS?

Thank you again for your responding so quickly.

 

[tommythewoo]

@R1CH Wow, MKV, that compression though...I never knew. Thank you for your help, valuable and changes a things considerably for the better.