search for: requantize

Hi, is there a good concept to lower the quality of a Theora stream without completely reencoding it? For example to make a lower bitrate stream out of a higher bitrate stream on the fly on some sort of proxy server. I am thinking about something like requantization. If you think requantization is also the best (or the only) option for Theora please let me know. Kind regards, Franz

Dear all, I have a wav file that when I try to encode with the FLAC Frontend, I get "ERROR: unsupported format type 3". When I open it with an audio editor I find it is 44100 / 32 bit. I requantized it to 16 bit using the default dither and then compressed it with FLAC to get a 61 Mbyte file (the original was about 347 Mbyte). Obviously, this altered somewhat the quality, although in an indiscernible way (for me, at least). However, as a last attempt, I used Winrar on the original file an...

...ontend, I > get "ERROR: unsupported format type 3". WAV format 3 is 32 bit IEEE float which is not supported by FLAC. > When I open it with an audio editor I find it is 44100 / 32 bit. 32 bit *floating point* values. WAV files can also contain 32 bit (integer) PCM. > I > requantized it to 16 bit using the default dither and then compressed it Maybe requantizing to 24 bit might have made more sense (and 24 bit PCM is handled by FLAC). > However, as a last attempt, I used Winrar on the original file and to my > surprise it was compacted to 79 Mb, only about 33% more t...

Hi, I am very new to Theora, having just started working through the code a few weeks ago. I am working on a requantization tool to reduce bit rates, hopefully on the fly, for some video conferencing work. As I was working through the encoding phase I noticed this line in encode.c: for(ti=_enc->dct_token_offs[pli][zzi];ti<ndct_tokens;ti++){ It's around line 804, but I am

Hi, After a quick read of the Theora spec, I became curious about the possibility of fast quality reduction of Theora videos. The idea is to decode through the Huffman and reverse prediction steps, and then to truncate the coefficients and reencode. My questions are: * Is this a reasonable way to reduce the quality and bitrate of a stream? Will it be comparable in quality to a complete

Hello, I understand the encoder provides an option for FEC to provide some protection against packet loss, but I don't understand the details of this arrangement. I'd appreciate answers to the following: * Adding FEC seems to change the encoded audio bit-stream itself, i.e., it doesn't just add additional protection bits, but also changes the encoded bits. This is easy to show by

Hello all. In the shower the other day (where most of this sort of musing gets done, eh?) I was thinking about graceful degradation of audio signals. Let me apologise in advance if these are elementary concepts or if I demonstrate a complete lack of insight -- I don't rate even a dabbler status in the area of audio codecs. Anyway: If we have a 128kbs signal coming down a *udp* channel with

Hi, I'm new to Theora and would like to propose several performance optimization using advanced instructions in x86 CPUs (SSE2-SSE4.2). There are several source files in \x86 and \x86_vc which developed using inline assembler. However this cause several maintenance problems: 1) Need to sync gcc & msvc versions 2) Only 32bit environment is supported 3) No support for newer than MMX