Question / Help FLV twice the size of mp4

[DaveBergeron]

I was recording in mp4 but I switched to flv since I read that if obs crashes the flv file will still be saved but mp4 will not. But I noticed flv files are over twice the size of mp4 file. Are flv files suppose to be bigger than mp4? And what do you record in, mp4 or flv?

 

[Boildown]

Are you sure you're using the exact same encoding settings with the same type of input video? Are you sure you didn't record for twice as long when doing .flv? What's the bitrate from your flv files vs your mp4 files (check the media info)?

I personally record .mp4 when doing NVEnc recording, because OBS has literally never crashed for me when I do NVEnc, over literally thousands of hours of recordings. When using x264 encoding, I'd definitely use .flv because it crashes sometimes, and .flv doesn't get corrupted when it crashes.

 

[DaveBergeron]

Here is the media info. The flv overall bit rate is higher, I don't know why. I even put smaller resolution and lower fps for the flv file.



General
Complete name : C:\Fraps\New folder\hs (04).flv
Format : Flash Video
File size : 263 MiB
Duration : 15mn 27s
Overall bit rate : 2 378 Kbps
Writing application : Open Broadcaster Software v0.657b
fileSize : 275706251.000

Video
Format : AVC
Format/Info : Advanced Video Codec
Format profile : Baseline@L3.1
Format settings, CABAC : No
Format settings, ReFrames : 1 frame
Codec ID : 7
Duration : 15mn 27s
Bit rate : 1 000 Kbps
Width : 1 280 pixels
Height : 720 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 17.000 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.064
Stream size : 111 MiB (42%)
Writing library : x264 core 146 r2538 121396c
Encoding settings : cabac=0 / ref=1 / deblock=0:0:0 / analyse=0:0 / me=dia / subme=0 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=0 / me_range=16 / chroma_me=1 / trellis=0 / 8x8dct=0 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=0 / threads=6 / lookahead_threads=1 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=0 / weightp=0 / keyint=250 / keyint_min=17 / scenecut=0 / intra_refresh=0 / rc=crf / mbtree=0 / crf=20.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=0
Color range : Limited
Color primaries : BT.709
Transfer characteristics : sYCC
Matrix coefficients : BT.709

Audio
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : 10
Duration : 15mn 27s
Bit rate : 128 Kbps
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz
Frame rate : 46.875 fps (1024 spf)
Compression mode : Lossy
Delay relative to video : 9ms
Stream size : 14.2 MiB (5%)







General
Complete name : C:\Fraps\New folder\Hearthstone (142).mp4
Format : MPEG-4
Format profile : Base Media
Codec ID : isom (isom/iso2/avc1/mp41)
File size : 118 MiB
Duration : 14mn 57s
Overall bit rate : 1 104 Kbps
Encoded date : UTC 2016-02-03 07:43:53
Tagged date : UTC 2016-02-03 07:43:53
Writing application : Open Broadcaster Software v0.657b

Video
ID : 2
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4
Format settings, CABAC : Yes
Format settings, ReFrames : 4 frames
Muxing mode : Container profile=High@3.1
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 14mn 57s
Source duration : 14mn 57s
Bit rate : 1 000 Kbps
Width : 1 600 pixels
Height : 900 pixels
Display aspect ratio : 16:9
Frame rate mode : Variable
Frame rate : 30.000 fps
Minimum frame rate : 29.412 fps
Maximum frame rate : 30.303 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.023
Stream size : 107 MiB (91%)
Source stream size : 107 MiB (91%)
Writing library : x264 core 146 r2538 121396c
Encoding settings : cabac=1 / ref=1 / deblock=1:0:0 / analyse=0x3:0x113 / me=hex / subme=2 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=0 / me_range=16 / chroma_me=1 / trellis=0 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=0 / threads=12 / lookahead_threads=4 / 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=1 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=10 / rc=cbr / mbtree=1 / bitrate=1000 / ratetol=1.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / vbv_maxrate=1000 / vbv_bufsize=1000 / nal_hrd=none / filler=1 / ip_ratio=1.40 / aq=1:1.00
Encoded date : UTC 2016-02-03 07:43:53
Tagged date : UTC 2016-02-03 07:43:53
Color range : Limited
Color primaries : BT.709
Transfer characteristics : sYCC
Matrix coefficients : BT.709
mdhd_Duration : 897333

Audio
ID : 1
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : 40
Duration : 14mn 57s
Source duration : 14mn 57s
Bit rate mode : Constant
Nominal bit rate : 128 Kbps
Channel(s) : channel0
Channel(s)_Original : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz
Frame rate : 46.875 fps (1024 spf)
Compression mode : Lossy
Source stream size : 10.1 MiB (9%)
Language : English
Encoded date : UTC 2016-02-03 07:43:53
Tagged date : UTC 2016-02-03 07:43:53
mdhd_Duration : 897280

 

[Sapiens]

You recorded the videos with completely different rate control settings. One uses a constant bitrate of 1000 Kbps, the other uses a variable bitrate, has no bitrate limitations, and instead targets a certain quality level.

 

[DaveBergeron]

Alright, thanks guys. I did change some settings since when I upgraded to windows 10, obs kept freezing. Would you recommend cbr or not? For recording, not streaming.

I had obs crash 2-3 times on me over last 2 years so flv seems better for me. I have AMD so I can't try NVEnc.

 

[Boildown]

You can use QP or CRF mode for local recordings, certainly. CBR mode wastes bits but is essential to streaming, and the bit wasting isn't really a factor except at higher bitrates anyways. So one hard rule is, always CBR for streaming, and the general rule for recording to hard drive is use a VBR method for more efficiency if available.

To directly answer your question, for local recording with x264, don't use CBR. Use a CRF instead. Guide: https://obsproject.com/forum/threads/how-to-make-high-quality-local-recordings.12600