120 FPS on a 720P broadcast

[nazopo]

Hello I have a FOX broadcast which is in its original broadcast form and VLC said its frame rate was 120 (119.880119). As we all know FOX broadcasts in 720p. On the other hand, NBC broadcasts at 1080i and VLC says it frame rate is 60 (59.940059). The ATSC standard didn't say anywhere that 720p can be 120 FPS neither did it say that 1080i can be 60FPS. So if anyone can explain what I do not understand that would be great.

[VLC_help]

What does tool called Mediainfo say about the file?

[Chancer]

In fact, 1080i broadcasts can have 29.97 frames/s (therefore 59.954 fields per second). But all progressive scan broadcasts are really up to 60 fps
http://en.wikipedia.org/wiki/Atsc#H.264.2FMPEG-4_AVC

[eltouco]

Hello I have a FOX broadcast which is in its original broadcast form and VLC said its frame rate was 120 (119.880119). As we all know FOX broadcasts in 720p. On the other hand, NBC broadcasts at 1080i and VLC says it frame rate is 60 (59.940059). The ATSC standard didn't say anywhere that 720p can be 120 FPS neither did it say that 1080i can be 60FPS. So if anyone can explain what I do not understand that would be great.

VLC seems to give to fields rate instead of the frame rate on certain type of video file (at lest MPEG file), I also have noticed that

[nazopo]

Here is the 720p info: General
Complete name : G:\HD Videos\American Idol - ''The winner is revealed'' (Recorded May 26, 2010, KDFWDT).mpg
Format : MPEG-PS
File size : 12.8 GiB
Duration : 2h 7mn
Overall bit rate : 14.4 Mbps

Video
ID : 224 (0xE0)
Format : MPEG Video
Format version : Version 2
Format profile : Main@High
Format settings, BVOP : Yes
Format settings, Matrix : Default
Duration : 2h 7mn
Bit rate mode : Variable
Bit rate : 14.1 Mbps
Nominal bit rate : 19.0 Mbps
Width : 1280 pixels
Height : 720 pixels
Display aspect ratio : 16:9
Frame rate : 59.940 fps
Standard : Component
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.255
Stream size : 12.6 GiB (98%)

Here is the 1080i info: General
Complete name : G:\HD Videos\0 1028 pm (Recorded May 15, 2010).mpg
Format : MPEG-PS
File size : 9.17 GiB
Duration : 1h 37mn
Overall bit rate : 13.5 Mbps

Video
ID : 224 (0xE0)
Format : MPEG Video
Format version : Version 2
Format profile : Main@High
Format settings, BVOP : Yes
Format settings, Matrix : Default
Duration : 1h 37mn
Bit rate mode : Variable
Bit rate : 12.9 Mbps
Nominal bit rate : 65.0 Mbps
Width : 1920 pixels
Height : 1080 pixels
Display aspect ratio : 16:9
Frame rate : 29.970 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Bits/(Pixel*Frame) : 0.207
Stream size : 8.73 GiB (95%)

Audio
ID : 128 (0x80)
Format : AC-3
Format/Info : Audio Coding 3
Mode extension : CM (complete main)
Duration : 1h 37mn
Bit rate mode : Constant
Bit rate : 384 Kbps
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Video delay : -558ms
Stream size : 266 MiB (3%)

Text
ID : 224 (0xE0)-608-1
Format : EIA-608
Muxing mode : MPEG Video / EIA-708
Muxing mode, more info : Muxed in Video #1
Stream size : 0.00 Byte (0%)


It makes more sense now, but how does progressive video have fields?

[eltouco]

Here is the 720p info: General
[....]
It makes more sense now, but how does progressive video have fields?

it doesn't, it is more like a VLC bug

[Jean-Baptiste Kempf]

Yep, file a bug on trac.

[VLC_help]

Or wrong info in the file. Does it help if you remux the file?

[eltouco]

Or wrong info in the file. Does it help if you remux the file?

I've noticed that on transport Stream from the Freebox TV, the info in the stream is correct, but VLC shows 50 fps where it is actually 25 fps.

[eltouco]

Yep, file a bug on trac.

here you are

ticket 3966

[eltouco]

Yep, file a bug on trac.

Jb : I read your request for a sample file on the ticket, but the size limit is far too low (256 kb for video file is too low) I don't have a sample that little
the best I have is 1.5 Mb.

maybe it would be a good idea to put this size up for the bug tracker of a video player.

[Jean-Baptiste Kempf]

ftp://streams.videolan.org/incoming/

[eltouco]

ftp://streams.videolan.org/incoming/

ok, I'll use that next time, I already had two file posted on a web space, here are the links

http://eltouco.chez.com/video_capture_2 ... rlaced).ts

http://eltouco.chez.com/video_capture%2 ... essive).ts

[CitizenX]

FYI,
I am also seeing an incorrect FPS value, running on Windows Vista .
The file is an mpeg 2 transport stream produced by TRANSGEnc Xpress 4.
It is set to have 29.97 fps but shows about twice that (59.94 fps) when I look at the codec info in VLC 1.1.2 (The Luggage).

However, ffmpeg shows the correct fps of 29.97 for the video stream,
an old version of ffmpeg running on Fedora Core 7.

[nazopo]

So I should wait for the next version in order to fix this problem?

[VLC_help]

They might be in next version or not. Easiest thing is to follow the trac ticket, there will be version number mentioned when issue is fixed.

[nazopo]

Thank You