[MPEG] Why initialize YUV = 128?

Started by Robert in comp.dsp16 years ago 5 replies

Hi all, I am reading MPEG source code. I found all the Y U V are initialized to 128. Why? Before the I picture transform, the source...

Hi all, I am reading MPEG source code. I found all the Y U V are initialized to 128. Why? Before the I picture transform, the source picture was subtract from a "virtual" reference picture(Y U V are all 128). What's it mean? Any suggestions will be appreciated! Best regards, Davy


MPEG-7 Descriptor Code Repository?

Started by Zhiguo in comp.dsp14 years ago

Is there a public source code repository of MPEG-7 visual descriptors? Recently I am extracting visual features from video files, such as Color...

Is there a public source code repository of MPEG-7 visual descriptors? Recently I am extracting visual features from video files, such as Color Moment, Edge Histogram, etc. I need some reference source code. How can I get it? Any help appreciated. Thanks in advance.


How to read Video only from MPEG file.

Started by Ravikiran in comp.dsp18 years ago 1 reply

Hai all, Is it possible to read Video (or Audio) only from a MPEG (4) file ?. If we can..how to do. Regards, Ravi.

Hai all, Is it possible to read Video (or Audio) only from a MPEG (4) file ?. If we can..how to do. Regards, Ravi.


Need MPEG Player that Can Save Each Decompressed Frame

Started by Jeremy Smith in comp.dsp17 years ago 1 reply

Hello. Is there a free/shareware MPEG player with the ability to allow me to save each decompressed frame as a JPEG/bitmap/etc. file? I need...

Hello. Is there a free/shareware MPEG player with the ability to allow me to save each decompressed frame as a JPEG/bitmap/etc. file? I need the ability to save 10 consecutive frames. Please respond to the newsgroup. The above e-mail address does not work.


visible MPEG decoding error

Started by Alexis in comp.dsp12 years ago 2 replies

Hi all, I'm a student and i have to do a research about diversity reception in DVB-T. Now i'm reading an article from this...

Hi all, I'm a student and i have to do a research about diversity reception in DVB-T. Now i'm reading an article from this link: http://www.dibcom.com/Images/Upload/pdf/Publications/Confluent.pdf. I don't understand the subjective failure point definition (page 4) : "maximum of one visible MPEG decoding error during 20 seconds". Please, i would like to know what does this definition means...


[MPEG] reference picture question

Started by Davy in comp.dsp16 years ago 3 replies

Hi all, I am reading MPEG's MSSG software implementation. fullsearch() function in motion.c input includes "source reference picture" and...

Hi all, I am reading MPEG's MSSG software implementation. fullsearch() function in motion.c input includes "source reference picture" and "reconstructed reference picture". AFAIK, all the reference picture(including I frame and P frame) should be reconstructed (by IDCT) before be used as reference. So what's these two reference's difference? Any suggestions will be appreciated! All...


Number of IDCTs for MPEG?

Started by Chris Bore in comp.dsp13 years ago 2 replies

Hi I'd appreciate a sanity check on my back-of-the-envelope calculation of the number of IDCTs needed in an MPEG decode. If we have PAL...

Hi I'd appreciate a sanity check on my back-of-the-envelope calculation of the number of IDCTs needed in an MPEG decode. If we have PAL 704x480 at 25 fps divided into 16x16 macroblocks, then we have 1320 macroblocks. If we are using YUV422 then each 16x16 macroblock has 4 8x8 blocks for Y and 2 each 8x8 block for U and V. If we do 8x8 IDCTs using a 1D 8-point IDCT then for each 8x8 ...


MPEG video compression

Started by jerome in comp.dsp16 years ago 5 replies

Hi guys, I'd like to know if some of you have already implemented MPEG (2 or 4) video compression on DSP. What free source codes have you used...

Hi guys, I'd like to know if some of you have already implemented MPEG (2 or 4) video compression on DSP. What free source codes have you used ? Could you give me some links to good free source codes ? I've searched on the net but haven't found anything really good. Thanks for your help. This message was sent using the Comp.DSP web interface on www.DSPRelated.com


Phase continuous waveform generation for ATSC (N.American Digital TV standard).

Started by Anonymous in comp.dsp16 years ago 7 replies

I am trying to generate a test waveform which is compatible with the ATSC standard. I am obtaining the MPEG packets from a TV clip obtained from...

I am trying to generate a test waveform which is compatible with the ATSC standard. I am obtaining the MPEG packets from a TV clip obtained from the web. I am ensuring that the MPEG packet frame rate of the transport stream packets is compatible with the ATSC standard. The waveform is converted from IQ --> RF and fed into a set top box, which decodes the signal and feeds the DVI output into a


MPEG2 motion search problem?

Started by Davy in comp.dsp16 years ago 1 reply

Hi all, I want to implement a encoder deal with I and P frame. So only one reference frame is stored for motion search. Is it the...

Hi all, I want to implement a encoder deal with I and P frame. So only one reference frame is stored for motion search. Is it the reconstructed forward frame? But the MSSG (http://www.mpeg.org/MPEG/MSSG/) encoder's full search function require 2 frames. Its integer full search is based on the "original source reference". And its half pel search (9 point related to the best integer) is...


Why can Matlab wavread() not read AAC .wav reference files?

Started by larr...@yahoo.com in comp.dsp15 years ago 8 replies

I try to use wavread() function to open/read .wav reference files for AAC (MPEG-2 AAC) compliance test provided by ISO/MPEG (ISO/IEC 13818-4)....

I try to use wavread() function to open/read .wav reference files for AAC (MPEG-2 AAC) compliance test provided by ISO/MPEG (ISO/IEC 13818-4). But I got the error message "Data compression format (Format #65534) is not supported". However, there is no problem for Adobe Audition and Microsoft Windows Media Player to open and play them. I'd appreciate it if anybody could tell me the reason why ...


Doubts about MPEG file reading.

Started by Ramya in comp.dsp18 years ago 1 reply

Hai all, I have some doubts about how we read the data from MPEG file. 1) Do we read Audio and Video simultaneously ? Or do we read one...

Hai all, I have some doubts about how we read the data from MPEG file. 1) Do we read Audio and Video simultaneously ? Or do we read one after another? Is free source code available to do so? 2) While we are reading the Video data, do we read them frame by frame or Block by Block (Macro)? If any of you know what are the steps to be taken to read the data from file, please help me...


h.264 or mpeg 4 or 263

Started by bubu in comp.dsp17 years ago 2 replies

HI I wonder whether the reference code of this coders is freely available? And where would that be? Bubu

HI I wonder whether the reference code of this coders is freely available? And where would that be? Bubu


Block based compression

Started by daisy21 in comp.dsp14 years ago

Hello, DOes anyone know of any efficient methods to compress parts of a video screen where perhaps motion is going on, ie a desktop playing an...

Hello, DOes anyone know of any efficient methods to compress parts of a video screen where perhaps motion is going on, ie a desktop playing an mpeg in the corner? Thanks


MPEG codecs resource?

Started by Jack in comp.dsp17 years ago 1 reply

Hello. Is there any good book that explains MPEG2, MPEG4, H.264, AAC algorithms and implementations? Or, any website would be great...

Hello. Is there any good book that explains MPEG2, MPEG4, H.264, AAC algorithms and implementations? Or, any website would be great too. Thanks! Jack


MDCT

Started by Anonymous in comp.dsp16 years ago 3 replies

Hi Guys, Can anyone explain me How is MDCT different from basic DCT? how does MDCT achieve Time Domain Alias Cancellation ( TDAC ) which is...

Hi Guys, Can anyone explain me How is MDCT different from basic DCT? how does MDCT achieve Time Domain Alias Cancellation ( TDAC ) which is useful in MPEG AUDIO compression. TIA. cheers. Bhanu


project

Started by pachu in comp.dsp18 years ago 3 replies

Hi all, I had posted a question a few days back, expressing that i was intended to do a mpeg coder decoder. From the replies that i got...

Hi all, I had posted a question a few days back, expressing that i was intended to do a mpeg coder decoder. From the replies that i got i have understood that it would a huge project. I shall express my wish. We are 3 guys here, we are actually want to explore the field of DSP (it is very vast, i am aware). Just learning from the book would not be enough. So we decided that we must ...


MPEG 4 Encoder at D1@30fps on BF561

Started by sagarshantraj in comp.dsp14 years ago 1 reply

Hi all, Has anyone achieved D1@30fps encoding on BF561 processor? And does splitting the code into different core's will help increase the...

Hi all, Has anyone achieved D1@30fps encoding on BF561 processor? And does splitting the code into different core's will help increase the frame rate? We are running at D1@10fps. Any algorithm implementation, approach , guidence will be helpful regarding this. Thanking you. Warm Regards, Sagar


Support? I am so mad at Analog Devices

Started by Randy Dawson in comp.dsp17 years ago 2 replies

I am using the 21xx family procesors, and I am sucking up information as fast as I can find it (Thanks Herman, bought your disk, I...

I am using the 21xx family procesors, and I am sucking up information as fast as I can find it (Thanks Herman, bought your disk, I love Aerospace Software!) OK I have the 2181 EZKIT, it sat around here for 5 years before I got serious, I was totaly impressed with the demos, Stairway to Heaven wow! The monitor source did not include the MPEG because it was from Xing and I understand that....


I need the results of porting MPEG2 on TI DSPs.

Started by ardestani in comp.dsp15 years ago 1 reply

Hi, I need the results of running MPEG-2 on TI DSPs such as c55x. i want to compare the reports of clock cycle consumed MPEG2 to be run on this...

Hi, I need the results of running MPEG-2 on TI DSPs such as c55x. i want to compare the reports of clock cycle consumed MPEG2 to be run on this DSP or another DSP with a ASIC architecture. Regards.