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Topic: why the hell they still using MP2 Now Adays in Broadcast Tv ?? (Read 14325 times) previous topic - next topic
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why the hell they still using MP2 Now Adays in Broadcast Tv ??

Hello Everyone i just wonder why mp2 still broadcast standard now aday !! at such low bitrates such as 128 and 192 .

any one have explanation why they stick to mp2 to now adays even in the HD channels ?? 
ichecked most of the broadcast equipment and they support aac codec family so why they stick to the old legacy codecs ?
also if u are taking about the decoders most of now adays decoders support aac format specially HD One . and offcourse 4k 

In Some satellites in Europe they use Ac3 Codec with high value bitrate such as 448 or 320 and its acceptable but what its not acceptable that you use old codecs with low bitrates .

any one have explanation why they still use mp2 in HD channels now adays ??

Re: why the hell they still using MP2 Now Adays in Broadcast Tv ??

Reply #1
The reason is very simple, MP2 is good enough. Also there are a few receivers out there which can't decode anything else but MP2.

Re: why the hell they still using MP2 Now Adays in Broadcast Tv ??

Reply #2
Also, broadcast equipment cost an arm and leg, and if you have solution that works, you don't change it.
TAPE LOADING ERROR

Re: why the hell they still using MP2 Now Adays in Broadcast Tv ??

Reply #3
The reason is very simple, MP2 is good enough. Also there are a few receivers out there which can't decode anything else but MP2.

For most people its ok but for audio caring people you will notice the difference espically in the music things which are common in broadcast so its not ok that u see audio on facebook at AAC 320kb and this shitty quality in broadcast

Re: why the hell they still using MP2 Now Adays in Broadcast Tv ??

Reply #4
Also, broadcast equipment cost an arm and leg, and if you have solution that works, you don't change it.

The Same encoders They use have AAC codecs so we arent talking about changing the equipment anymore

Re: why the hell they still using MP2 Now Adays in Broadcast Tv ??

Reply #5
The reason is very simple, MP2 is good enough. Also there are a few receivers out there which can't decode anything else but MP2.

For most people its ok but for audio caring people you will notice the difference espically in the music things which are common in broadcast so its not ok that u see audio on facebook at AAC 320kb and this shitty quality in broadcast

No one cares about minor differences in audio quality for broadcast TV.  If the audio is understandable, that is good enough.

Re: why the hell they still using MP2 Now Adays in Broadcast Tv ??

Reply #6
The reason is very simple, MP2 is good enough. Also there are a few receivers out there which can't decode anything else but MP2.

For most people its ok but for audio caring people you will notice the difference espically in the music things which are common in broadcast so its not ok that u see audio on facebook at AAC 320kb and this shitty quality in broadcast

Something important to notice here is that upgrading quality on Facebook, Youtube, torrented movie files etc is easy. When a new codec comes out, just update the software, update the browser, whatever.

The difference with broadcast is that hardware (not software) already exists. It cannot be updated. When digital broadcasting was starting in Europe (for example) 15 years ago, it was a huge deal changing people with analog TVs over to digital. It needed a huge push from governments to raise awareness that the old analog TV receivers will stop working. Every small house in the countryside, every TV in every school, hospital, you name it, everywhere had to replace their analog TVs with digital. And the standard 15 years ago that they moved to was pretty much MP2 for audio.

The hardware (not software) decoder boxes that everyone in Europe (and the world?) upgraded to back then decoded MP2 only. It's just not possible to suddenly turn off that support now.  MP2 must be used, or people who bought decoders in the past ten years all have to upgrade, needing another massive awareness campaign from governments, broadcasters, etc to every single person in the world effectively.   And of course us tech-savvy posters on HA are very happy upgrading our hardware every few years, but for TV as a service to work for the entire population, you can't just break that because a tiny percentage of nerds (me included) want an upgrade in quality.

Maybe there will be a slow transition eventually, but it would take decades.

Re: why the hell they still using MP2 Now Adays in Broadcast Tv ??

Reply #7
You are right im with you But why you at least get the bitrate high above 300 in my country satellite use only 128 for most tvs and the top paid tv use 192 only a few use high bitrates up to 384kb/s

Those 200kb wont affect the pciture anyway but offcourse will affect the Quality.

Re: why the hell they still using MP2 Now Adays in Broadcast Tv ??

Reply #8
You have to understand that satellite bandwidth is expensive, even nowadays, so to save the costs, they reduced audio bandwidth. It may seem small reduction, but it affects monthly and annual fees - 24/7 streaming doesn't come off cheap.
TAPE LOADING ERROR

Re: why the hell they still using MP2 Now Adays in Broadcast Tv ??

Reply #9
I think that's down to space on the mux.

Frequencies (or parts of the frequency spectrum) cost money to own for satellite, or for terrestrial transmission. You often hear of high bidding prices to win parts of the spectrum. Once broadcasters have a certain frequency to use, there's only a certain amount of bandwidth they have there, they used lower audio bitrates back at the start of DVB, and say 6 TV channels (video+audio) fit on one frequency. Increasing the audio bitrate means you can't fit 6 TV channels any more, you have to bump one of those off on to another frequency, and have less channels all round.

From the broadcasters point of view, if you can reduce audio bitrate enough to squeeze in one more TV channel on a frequency, you get a lot of advertising revenue from selling ad breaks on that TV channel. If you drop that TV channel and instead go for higher audio bitrate on all the others you get... well not much. Some audiophiles are a bit happier, which of course means nothing much to TV broadcasters unless they can market it as "HD Audio" or some flashy name to get more subscribers, but it's still just MP2.  Increasing audio bitrate on a given channel in exchange for lower video quality is probably something advertisers would not want either.  They're paying for TV ads, not radio, so they want their product to be seen in good picture quality, the quality of the voice over on the ad matters less.

I know that broadcasters can and do charge companies more to get their ads shown on HD channels vs SD because of the better picture quality of the ad. I don't think they could charge more from having the audio on their ads running at 320k MP2 compared to 128k.

So cost, basically is the answer I guess. Increasing bitrates on Youtube etc has very low cost, but much higher cost on broadcast satellite or terrestrial.

Re: why the hell they still using MP2 Now Adays in Broadcast Tv ??

Reply #10
YouTube uses Opus and AAC at 128kbps even with HD. YouTube also follows an example of technology that gives you the option to stream using different codecs.

Another reason why AC3 might not be used (apart from limited regional support) is because it's not cheap to get a professional encoder, that the best MP2 encoder could do a better job at lower bit rates. AC3 can sound really bad at 128kbps. LC-AAC doesn't have the licensing fees it used to have, and is more capable at quality than AC3, but AAC encoders generally miss certain fidelity that a standard AC3 encoder covers at 320-448k (not that the overall quality is always good), much like a current-day transform codec like Opus can do a better job at fidelity at 128k. AC3 really was a good codec at the time IMO despite having a lower temporal resolution.

Re: why the hell they still using MP2 Now Adays in Broadcast Tv ??

Reply #11
MP2 works on any TV or box. AAC works on most newer equipment, but is typically limited to LC-AAC. I'm working on headend in cable operator and have a lot of problems with new services with AAC audio. One of major distributor in region switched to 48 kbps HE-AACv2 audio and it works great on most TV's, but sounds horrible on chinese boxes (mono sound with limited bandwidth). Software transcoders are unreliable with multicast, hardware transcoder (we use Harmonic) is very expensive. So MP2 is safe bet and 192 kbps gives reasonable quality.
As far as bitrate is concerned, typical video bitrate on HD video is 8 Mbps, so the savings on audio bitrate is irrelevant.
--------------------

Re: why the hell they still using MP2 Now Adays in Broadcast Tv ??

Reply #12
Any codec is fine as long as they use a bitrate that is known to be transparent for the encoder being used. For MP2 >= 256Kbps should be OK-ish for most people. Any lower than that and it gets a bit annoying. However I don't think HE-AAC should ever be used for broadcast TV.
Our local DVB-T2 transmissions use 64Kbit/s HE-AAC audio streams and they are truly horrible.

Quote
You have to understand that satellite bandwidth is expensive, even nowadays, so to save the costs, they reduced audio bandwidth. It may seem small reduction, but it affects monthly and annual fees - 24/7 streaming doesn't come off cheap.
If for example they have a channel with a 3Mbit/s video stream and a 128Kbps MP2 audio stream then I doubt cutting 128Kbps from the video and allocation it the audio stream will severely hurt the video quality

Re: why the hell they still using MP2 Now Adays in Broadcast Tv ??

Reply #13
TV broadcasters does't seek audio transparency, but to satisfy the majority (compatibility); most of the content is speech and MP2 does a good job. Also, TV speakers aren't of good quality, especially for music playback.
I beleive that stations with music content have higher bitrate audio stream, as sports channels have greater video bitrates for better motion quality.
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Re: why the hell they still using MP2 Now Adays in Broadcast Tv ??

Reply #14
You are right im with you But why you at least get the bitrate high above 300 in my country satellite use only 128 for most tvs and the top paid tv use 192 only a few use high bitrates up to 384kb/s

Those 200kb wont affect the pciture anyway but offcourse will affect the Quality.

This data came from VideoReDo of a CBS file I recorded off air 12-24-20. The other networks are very similar.

 File:                                     Name : \\mom-PC2\TV aux mom2\CBS Thu 8-11_20201224_1959.ts
                                           Size : 14.951 GB
                                       Duration : 03:02:48.13
                                       Mux type : TS Stream
                                    TS mux rate : 13.778 Mbps
 Video:                                Encoding : MPEG2
                                  VideoStreamID : x31
                                     Frame rate : 29.97 fps
                                  Encoding size : 1920 x 1080
                                   Aspect ratio : 16:9
                                Header bit rate : 17.598 Mbps
                                     VBV buffer : 976 KBytes
                                        Profile : Main@High
                                    Progressive : Prog or Int
                                         Chroma : 4:2:0
                                       Bit rate : 9.916 Mbps
                                     Captioning : EIA 608/708
                                    Field order : Top field first
 Audio Stream: 1 (Primary)                Codec : AC3
                                         Format : AC3 stream
                                       Channels : 5.1
                                       Language : eng
                                            PID : x34
                                  PES Stream Id : xBD
                                       Bit rate : 384 Kbps
                                  Sampling rate : 48000
                                    Sample size : 16 bits
 Audio Stream: 2                          Codec : AC3
                                         Format : AC3 stream
                                       Channels : 2.0
                                       Language : spa
                                            PID : x35
                                  PES Stream Id : xBD
                                       Bit rate : 192 Kbps
                                  Sampling rate : 48000
                                    Sample size : 16 bits

Broadcast TV audio is actually quite impressive.

Merry Christmas

Re: why the hell they still using MP2 Now Adays in Broadcast Tv ??

Reply #15
Thanks all for your replays , iappreciate it

Re: why the hell they still using MP2 Now Adays in Broadcast Tv ??

Reply #16
TV broadcasters does't seek audio transparency, but to satisfy the majority (compatibility); most of the content is speech and MP2 does a good job. Also, TV speakers aren't of good quality, especially for music playback.
I beleive that stations with music content have higher bitrate audio stream, as sports channels have greater video bitrates for better motion quality.

But MP2 is more robust to artifacts and should be transparent by 192kbps?. The issue here is that many are forced to use 80 ~ 160kbps when AAC/Opus would be a better choice.
Got locked out on a password i didn't remember. :/

Re: why the hell they still using MP2 Now Adays in Broadcast Tv ??

Reply #17
TV broadcasters does't seek audio transparency, but to satisfy the majority (compatibility); most of the content is speech and MP2 does a good job. Also, TV speakers aren't of good quality, especially for music playback.
I beleive that stations with music content have higher bitrate audio stream, as sports channels have greater video bitrates for better motion quality.

But MP2 is more robust to artifacts and should be transparent by 192kbps?. The issue here is that many are forced to use 80 ~ 160kbps when AAC/Opus would be a better choice.
MP2 isn't transparent at 192 kbps, but it's reasonable with a 13KHz lowpass, just as TV broadcasts and FM traditionally cut off at 15KHz or below.

Re: why the hell they still using MP2 Now Adays in Broadcast Tv ??

Reply #18
TV broadcasters does't seek audio transparency, but to satisfy the majority (compatibility); most of the content is speech and MP2 does a good job. Also, TV speakers aren't of good quality, especially for music playback.
I beleive that stations with music content have higher bitrate audio stream, as sports channels have greater video bitrates for better motion quality.

But MP2 is more robust to artifacts and should be transparent by 192kbps?. The issue here is that many are forced to use 80 ~ 160kbps when AAC/Opus would be a better choice.
MP2 isn't transparent at 192 kbps, but it's reasonable with a 13KHz lowpass, just as TV broadcasts and FM traditionally cut off at 15KHz or below.

Sounds a heck of a lot better than the AAC codecs used on DAB/Freeview/Sat, that choke on complex music(rock, classical, electro) because they use 56 ~ 128kbps. Here in the UK BBC R3 used 256k MP2 with what i assume is the TooLame encoder.
Got locked out on a password i didn't remember. :/

 

Re: why the hell they still using MP2 Now Adays in Broadcast Tv ??

Reply #19
Here in the UK BBC R3 used 256k MP2 with what i assume is the TooLame encoder.

I really can't imagine that BBC uses TooLame. In Germany we use MP2 developed by Institut für Rundfunktechnik. Surely BBC has their own Institutes for soft- and hardware development. Just remember their loudspeaker research in the 1970 and 1980 decades.

Re: why the hell they still using MP2 Now Adays in Broadcast Tv ??

Reply #20
I really can't imagine that BBC uses TooLame. In Germany we use MP2 developed by Institut für Rundfunktechnik. Surely BBC has their own Institutes for soft- and hardware development. Just remember their loudspeaker research in the 1970 and 1980 decades.

Apparently their MP2 implementation won an Emmy award in 2000. Sadly the institute will be closed for good on 31 December 2020.

Re: why the hell they still using MP2 Now Adays in Broadcast Tv ??

Reply #21
You are right im with you But why you at least get the bitrate high above 300 in my country satellite use only 128 for most tvs and the top paid tv use 192 only a few use high bitrates up to 384kb/s

Those 200kb wont affect the pciture anyway but offcourse will affect the Quality.

This data came from VideoReDo of a CBS file I recorded off air 12-24-20. The other networks are very similar.

 File:                                     Name : \\mom-PC2\TV aux mom2\CBS Thu 8-11_20201224_1959.ts
                                           Size : 14.951 GB
                                       Duration : 03:02:48.13
                                       Mux type : TS Stream
                                    TS mux rate : 13.778 Mbps
 Video:                                Encoding : MPEG2
                                  VideoStreamID : x31
                                     Frame rate : 29.97 fps
                                  Encoding size : 1920 x 1080
                                   Aspect ratio : 16:9
                                Header bit rate : 17.598 Mbps
                                     VBV buffer : 976 KBytes
                                        Profile : Main@High
                                    Progressive : Prog or Int
                                         Chroma : 4:2:0
                                       Bit rate : 9.916 Mbps
                                     Captioning : EIA 608/708
                                    Field order : Top field first
 Audio Stream: 1 (Primary)                Codec : AC3
                                         Format : AC3 stream
                                       Channels : 5.1
                                       Language : eng
                                            PID : x34
                                  PES Stream Id : xBD
                                       Bit rate : 384 Kbps
                                  Sampling rate : 48000
                                    Sample size : 16 bits
 Audio Stream: 2                          Codec : AC3
                                         Format : AC3 stream
                                       Channels : 2.0
                                       Language : spa
                                            PID : x35
                                  PES Stream Id : xBD
                                       Bit rate : 192 Kbps
                                  Sampling rate : 48000
                                    Sample size : 16 bits

Broadcast TV audio is actually quite impressive.

Merry Christmas


The USA uses Dolby Digital (AC3) in over the air broadcasts and the main HD channels are typically 5.1 with 384 kbps for the main audio program with 192 kbps for the second audio program (descriptive audio or Spanish audio).  USA broadcast TV standard is ATSC.  I can't imagine audio being bad for most people unless you're in the group that needs to use the SAP and still wants 5.1 or something.  To be fair the SAP always sucked in quality even more so in the days of analog TV.  There's a limit of about 480 kbps max per channel for this standard when it comes to audio.  Even standard definition sub channels often have good 2 channel audio as well.

MP2 seems to be used in European territories according to this topic possibly without a standard set of rules for allowed bitrates?  I love to know what the standards are there?  I've heard of overseas radio stations broadcasting music in mono for example.

Re: why the hell they still using MP2 Now Adays in Broadcast Tv ??

Reply #22
MP2 is in the old obsolete DAB standard, that was widely planned but never widely used in Europe. I don't know which country OP refers to.

There are reasons why it was abandoned, but there are reasons for a radio station to stick to what they already have, and I can also only speculate that some broadcasters have kept the MP2 transmissions rather than hiring staff to handle complaints from people who would lose the signal that their neighbours apparently still get. MP2 for radio was of course optimized for that purpose - which does cost bits compared to MP3 for file playback! - and back in the day of plusless DAB, BBC's R&D department recommended bitrates at 256 or 224, only in some cases accepting a further reduction to 192 kbit/s.

DAB+ (with the + yes) was also totally abandoned in North America. It has support for more-than-good-enough audio quality, but also permits a low minimum bitrate. I guess the bad rap for sound quality is just as much bad rap for dishonest marketing when they tout bitrates they don't use.

Re: why the hell they still using MP2 Now Adays in Broadcast Tv ??

Reply #23
MP2 is in the old obsolete DAB standard, that was widely planned but never widely used in Europe. I don't know which country OP refers to.

Yeah, MP2 was supposed to be used with DAB, DAB+ uses HE-AACv2. But MP2 is still being used for DVB (at least in Germany), many TV stations also use AC3 but MP2 is still there as a fallback if AC3 doesn't work.

It could be possible that this is only valid for SD and HD uses H.264 and AC3 as standard.

Re: why the hell they still using MP2 Now Adays in Broadcast Tv ??

Reply #24
Yeah and also MP2 got into hardware decoder chips quite early, even before DVD-video (and thereby more TV signal decoder chips) got MP2 and AC3 mandated.

Edit: That's DVD with PAL. On NTSC I see there is no requirement to have MP2. But I can only guess then that there was a reason to make it mandatory in the part of the world where MP2 was widely used in broadcast.