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Betamax76

join:2008-10-16
Canonsburg, PA
reply to icemannyr1

[Channels] Re: MPEG-4 is now being used for the .TV channels

said by icemannyr1:

Does anyone know if QVC HD is MPEG2 or MPEG4?
I've noticed the max bit rate is 12.4 MB's while the other HD shopping channel HSN HD is 17.9 MB's.
Is QVC HD being re compressed or just sent at a lower bit rate?

QVC HD is sharing a QAM frequency with 3 channels being sent in MPEG-2 and is being recompressed.

* QAM 52 (393 MHz): 650 QVC HD, 668 Destination America HD, 739 Hallmark Movie Channel (MPEG-2)

Meanwhile, HSN HD is on a QAM frequency with only 2 channels and is being sent without recompression:

* QAM 30 (261 MHz): 651 HSN HD, 1001 PPV HD (MPEG-2)

The Weather Channel HD has the same 2 to 1 MPEG-2 channel loading and should be sent to Fios set top boxes exactly as received at the super headend:

* QAM 18 (147 MHz): 595 YES HD, 619 Weather Channel HD (MPEG-2)

PJL

join:2008-07-24
Long Beach, CA
kudos:2

said by Betamax76:

QVC HD is sharing a QAM frequency with 3 channels being sent in MPEG-2 and is being recompressed.

"Recompressed?" If the total bandwidth or the three sources is less than the capacity of one QAM channel (which is the case for those channels that are three-to-one QAM), then none is recompressed. Verizon does not "recompress."

tnsprin

join:2003-07-23
Bradenton, FL
kudos:1

Actually they have to for many channels now being sent as Mpeg-4 and still being presented on FIOS as mpeg-2. Hopefully they will eventually eliminate that.


PJL

join:2008-07-24
Long Beach, CA
kudos:2

1 edit

said by tnsprin:

Actually they have to for many channels now being sent as Mpeg-4 and still being presented on FIOS as mpeg-2. Hopefully they will eventually eliminate that.

That is true, but they are not "recompressed" but rather "re-encoded" to MPEG-2 after they are decoded from MPEG-4. Compression and encoding are not the same except in the sense that any encoding reduces the bit being sent. "Recompression" to me means taking a signal, encoding it, and then compressing it further beyond the encoding standard by changing the normal encoding to reduce the bit rate. Symantecs perhaps.

ALbino

join:2003-02-01
Chino Hills, CA
reply to Betamax76

Is there a way to tell on my TiVo XL4 which channels are MPEG-2 and which are h.264? Really, I'd like to know in KMTTG, but I'd settle for either way.


nowayout

join:2009-06-22
Allentown, PA

said by ALbino:

Is there a way to tell on my TiVo XL4 which channels are MPEG-2 and which are h.264? Really, I'd like to know in KMTTG, but I'd settle for either way.

You can, but you have to dig for it. Tune to a channel, and then go into settings > Remote, Cablecard & Devices > cablecard decoder > CC Options > DVR Diagnostics

Scroll down to the channel in question and you can see its associated data.

ALbino

join:2003-02-01
Chino Hills, CA

Yikes. Good to know though, thanks


MURICA

join:2013-01-03
reply to PJL

said by PJL:

said by tnsprin:

Actually they have to for many channels now being sent as Mpeg-4 and still being presented on FIOS as mpeg-2. Hopefully they will eventually eliminate that.

That is true, but they are not "recompressed" but rather "re-encoded" to MPEG-2 after they are decoded from MPEG-4. Compression and encoding are not the same except in the sense that any encoding reduces the bit being sent. "Recompression" to me means taking a signal, encoding it, and then compressing it further beyond the encoding standard by changing the normal encoding to reduce the bit rate. Symantecs perhaps.

Re-encoding and re-compressing are the same thing. Every time you re-encode a lossy codec to another lossy codec there is a quality loss.

Verizon could be re-encoding the H.264 feeds they are receiving to MPEG-2 at a bitrate of 1,000 Mbps and there would still be some quality loss.

PJL

join:2008-07-24
Long Beach, CA
kudos:2

said by MURICA:

said by PJL:

said by tnsprin:

Actually they have to for many channels now being sent as Mpeg-4 and still being presented on FIOS as mpeg-2. Hopefully they will eventually eliminate that.

That is true, but they are not "recompressed" but rather "re-encoded" to MPEG-2 after they are decoded from MPEG-4. Compression and encoding are not the same except in the sense that any encoding reduces the bit being sent. "Recompression" to me means taking a signal, encoding it, and then compressing it further beyond the encoding standard by changing the normal encoding to reduce the bit rate. Symantecs perhaps.

Re-encoding and re-compressing are the same thing. Every time you re-encode a lossy codec to another lossy codec there is a quality loss.

Verizon could be re-encoding the H.264 feeds they are receiving to MPEG-2 at a bitrate of 1,000 Mbps and there would still be some quality loss.

But upon re-encoding you can compress beyond the actual re-encoding, Verizon does not do that.


wmcbrine
213 251 145 96

join:2002-12-30
Laurel, MD
kudos:1
reply to nowayout

said by nowayout:

Tune to a channel, and then go into settings > Remote, Cablecard & Devices > cablecard decoder > CC Options > DVR Diagnostics

Alternatively:
Settings & Messages > Account & System Info > DVR Diagnostics
--
09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0

UnnDunn
Premium
join:2005-12-21
Brooklyn, NY
reply to PJL

said by PJL:

But upon re-encoding you can compress beyond the actual re-encoding, Verizon does not do that.

There is no such thing as the "actual re-encoding". Encoding and compression are not two separate steps. Encoding is compression.

PJL

join:2008-07-24
Long Beach, CA
kudos:2

said by UnnDunn:

said by PJL:

But upon re-encoding you can compress beyond the actual re-encoding, Verizon does not do that.

There is no such thing as the "actual re-encoding". Encoding and compression are not two separate steps. Encoding is compression.

I guess I didn't make my point clearly. It is just that when encoding, extra compression (beyond the normal encoding) can be performed on the stream. Verizon does not do that.

wizziwig

join:2013-01-25

said by PJL:

I guess I didn't make my point clearly. It is just that when encoding, extra compression (beyond the normal encoding) can be performed on the stream. Verizon does not do that.

I think your point would be easier to understand if you drop the whole encoding vs. compression argument (they are the same thing). What you really mean is that Verizon does not reduce bitrate when they re-encode.

As others have pointed out, even at equal or higher bitrates there would still be some quality loss when going from one lossy format to another - especially when real-time encoding is involved. This is why they need to stop converting all the native MPEG4 channels to MPEG2 - this includes all premiums like SHO, HBO, MAX, etc.

webcobbler

join:2013-03-09
Rumson, NJ
kudos:1
reply to PJL

I just thought of this.

Since now Goal Line is MPEG4. Which I do not really see a better picture from, in comparison to the MLB Extra Innings channels being in MPEG4.

Since it is, however they look in on channels that are MPEG2 (ESPN channels, BTN etc) , how can Goal Line, or FIOS for that matter benefit from making it MPEG4?

To me, If the channels they were looking in on , were channels that were all MPEG4, then that would make sense.


webcobbler

join:2013-03-09
Rumson, NJ
kudos:1

On another point

Will the Red Zone channel be transitioned to MPEG4?

To me, that would make a lot of sense, being that it is a seasonal channel. As well as people need to subscribe to it (minus the Ultimate Package customers.)



aaronwt
Premium
join:2004-11-07
Woodbridge, VA

2 edits
reply to wmcbrine

said by wmcbrine:

said by nowayout:

Tune to a channel, and then go into settings > Remote, Cablecard & Devices > cablecard decoder > CC Options > DVR Diagnostics

Alternatively:
Settings & Messages > Account & System Info > DVR Diagnostics

Yes, that is the way to get to it. The other post was a round about way to get to the same screen.

I just hope they transition more channels to H.264. I wish they would switch all of the channels. Since that would free up bandwidth for more channels and it also allows us to record more shows with the same amount of hard drive space since a show in H.264 will take up less space than one using MPEG2.

It won't be long before this 3TB drive in my TiVo Roamio Pro gets full so the more H.264 channels the better. I'm already using 40% of the storage space after 8 days. Once the new TV season starts up I will be getting closer to 100% full.

crgauth

join:2004-05-18
Glen Burnie, MD

I don't understand people that fill a 3TB drive.
Are you keeping shows for historical purpose (vs burning to DVD).
That would make some sense.
I would just be concerned that you are a HD failure away from losing all that content.


UnnDunn
Premium
join:2005-12-21
Brooklyn, NY
reply to PJL

said by PJL:

I guess I didn't make my point clearly. It is just that when encoding, extra compression (beyond the normal encoding) can be performed on the stream. Verizon does not do that.

No, you aren't understanding this. There is no such thing as "extra compression" or "normal encoding." There just isn't.

The very act of encoding in MPEG2 or MPEG4 is compression. When you take something that was already compressed in MPEG4 and re-encode it into MPEG2, that is another round of compression of an already-compressed video. There is simply no other way to express this. It's like making a photocopy of a photocopy--it doesn't matter how good the copier is, the second copy is always going to look worse than the first, because the act of copying degrades the image.

thetick

join:2009-06-22
White Plains, NY

What PJL means Verizon does not compress feeds more than what is delivered from the source.

Most (almost all) other providers re-encode at lower bit rate the program source so more channels can be fit in a smaller bandwidth. Depending on your definitions re-encoding at a lower bit rate could be considered "extra compression".


knarf829

join:2007-06-02
kudos:1

said by thetick:

What PJL means Verizon does not compress feeds more than what is delivered from the source.

Most (almost all) other providers re-encode at lower bit rate the program source so more channels can be fit in a smaller bandwidth. Depending on your definitions re-encoding at a lower bit rate could be considered "extra compression".

But Verizon takes sources that are MPEG4 and compresses them to MPEG2 (re-encoding / re-compressing in another format / extra compression), which degrades the signal as compared to how it was originally delivered to Verizon.


Greg2600

join:2008-05-20
Belleville, NJ
reply to Betamax76

FWIW, Time Warner is currently running commercials taking aim at the lack of HD on FIOS.



matcarl
Premium
join:2007-03-09
Franklin Square, NY

said by Greg2600:

FWIW, Time Warner is currently running commercials taking aim at the lack of HD on FIOS.

They are trying to get back the subs they lost to Fios in their month long CBS dispute.


nascar

join:2000-02-28
Verona, NJ
kudos:2
reply to Betamax76

FiOS has 139 Wide HD's compared to 106 Wide HD's for TWC. Hmmmm... I guess less is more.

But there are like over 200 HD's we still don't have!



dcowboy

join:2012-05-10

Limited is still fulltime so with the RSNs its:
twc = 187
fios = 157

said by nascar:

FiOS has 139 Wide HD's compared to 106 Wide HD's for TWC. Hmmmm... I guess less is more.

But there are like over 200 HD's we still don't have!


blue_trooper

join:2007-04-17
Exton, PA
reply to knarf829

While I'll buy that the MP4 -> MP2 encoding process may impact signal quality that does not mean that the conversion equals compression.

BTW - You are aware that the MP2 streams are actually bigger than the corresponding MP4 streams.


knarf829

join:2007-06-02
kudos:1

1 recommendation

said by blue_trooper:

While I'll buy that the MP4 -> MP2 encoding process may impact signal quality that does not mean that the conversion equals compression.

BTW - You are aware that the MP2 streams are actually bigger than the corresponding MP4 streams.

MPEG2 is a lossy compression format, so, yes, conversion to MPEG2 does equal compression.

Yes, I am aware that MPEG2 needs more bitrate than MPEG4 for equal quality. It doesn't change the fact that recompressing MPEG4 as MPEG2 decreases quality as compared to the original source. Just like if you were to take an audio MP3 at 128 kb/s and transcode it to 320 kb/s, the 320 kb/s will sound worse.

blue_trooper

join:2007-04-17
Exton, PA

said by knarf829:

Yes, I am aware that MPEG2 needs more bitrate than MPEG4 for equal quality. It doesn't change the fact that recompressing MPEG4 as MPEG2 decreases quality as compared to the original source.

I am bolding your words where you admit that equal quality is possible and what half of us are telling you is what Verizon is doing.

MPEG4 is also a lossy format, it's just more efficient at it than MPEG2.

knarf829

join:2007-06-02
kudos:1

3 recommendations

Exactly not what I said. You take an UNCOMPRESSED SOURCE and compress it to MPEG2 it will be a larger file than if you take an UNCOMPRESSED SOURCE and compress it to MPEG4 at the same quality.

If you take any compressed source and compress it to another format - adding EXTRA COMPRESSION - you will wind up with a video of lesser quality no matter the file size

MPEG2 is a COMPRESSED SOURCE. MPEG4 is a COMPRESSED SOURCE. Transcoding one to the other will result in a worse looking video than you started out with even though going from 4 to 2 results in a larger file.


blue_trooper

join:2007-04-17
Exton, PA

You're really not getting it.


knarf829

join:2007-06-02
kudos:1

1 recommendation

You should ask for help in the A/V forum if you don't understand lossy and lossless A/V file handling. Seems to be going of the rails in this forum.