On 9 September 2010 05:11, Vitor Sessak <[email protected]> wrote: > On 09/09/2010 02:50 AM, Marcelo Galvão Póvoa wrote: >> >> On 8 September 2010 06:54, Vitor Sessak<[email protected]> wrote: >>> >>> On 09/07/2010 03:21 AM, Marcelo Galvão Póvoa wrote: >>>> >>>> Hello, >>>> >>>> On 6 September 2010 10:13, Ronald S. Bultje<[email protected]> >>>> wrote: >>>>> >>>>> Hi, >>>>> >>>>> On Mon, Sep 6, 2010 at 5:54 AM, Vitor Sessak<[email protected]> >>>>> wrote: >>>>>> >>>>>> On 09/06/2010 02:46 AM, Marcelo Galvão Póvoa wrote: >>>>>>> >>>>>>> Ok, fortunately I've found the bug! >>>>>>> >>>>>>> It was just a MIN_ISF_SPACING parameter which I extracted from the >>>>>>> reference code but was unsure about it's Q level. After some time, I >>>>>>> thought I have it figured out but I was wrong. Now I know the answer >>>>>>> the hard way... >>>>>>> >>>>>>> The clipping and the sharp peaks are gone, the waveforms are really >>>>>>> close now! >>>>>> >>>>>> That's great news! >>>>>> >>>>>>> Also, the stddev against the reference decoder decreased a >>>>>>> lot (it was ~884 before): >>>>>>> all_men.awb stddev: 51.72 PSNR: 62.05 MAXDIFF: 1089 bytes: >>>>>>> 473600/ >>>>>>> 473600 >>>>>> >>>>>> stddev of 51 looks pretty good to me for this case. >>>>> >>>>> Maxdiff of 1089 looks like a lot to me, with a low stddev that >>>>> suggests that one particular part is off. Can you trace which part is >>>>> off and why (phase shift vs. actual bug)? >>>>> >>>> >>>> Sorry, but can you suggest a way of doing it? >>> >>> Your method of inverting one sample and summing in audacity would work on >>> showing where it is happening (some point will have an amplitude of >>> 1089). >>> To know if is a phase shift or a bug, you will have to compare visually >>> both >>> waves. >>> >> >> I don't know exactly how to detect a phase shift this way but the >> difference waveform I obtained [1] has some peaks at the sibilant >> parts I think. Probably just where the high band is louder. >> >>>> Also, what do MAXDIFF >>>> and the "2" at the end of the command line mean? >>> >>> MAXDIFF is the biggest difference among two samples. The "2" at the end >>> of >>> the command line says to read two-byte integers (16-bit). If you were >>> comparing video pixels, you would use "1". You can also see the source of >>> tiny_psnr.c, it is pretty simple. >>> >>>> This sample have long silence parts and I'm comparing my floating >>>> point implementation to the reference 16-bit fixed point. How close >>>> you think they should be? >>> >>> A very small stddev (< 1.00) would assure there is no bug in your >>> decoder, >>> but the fact that it is large does not means there is one. >>> >>> I suggest you do the following test: >>> >>> a) Get a biggish file (> 30 minutes) >>> b) Convert it to the a WAV with the sample rate and number of channel the >>> AMR encoder takes as input >>> c) Encode the file obtained in (b) it with the reference encoder >>> d) Decode the file obtained in (c) with the reference decoder >>> e) Decode the file obtained in (c) with ffamrwb >>> f) Compare the stddev of files obtained in (b) and (d) with that of (b) >>> and >>> (e). If file decoded with ffamr are as close to the original as that >>> decoded >>> with the reference decoder, it's good. >>> >> >> Results: >> $ ./tests/tiny_psnr ~/ref_pod.wav ~/orig_pod.wav 2 >> stddev: 2599.69 PSNR: 28.03 MAXDIFF:39592 bytes: 76480640/ 76480660 >> $ ./tests/tiny_psnr ~/my_pod.wav ~/orig_pod.wav 2 >> stddev: 2600.02 PSNR: 28.03 MAXDIFF:39653 bytes: 76480640/ 76480660 >> $ ./tests/tiny_psnr ~/my_pod.wav ~/ref_pod.wav 2 > > > Hmm, the files have different sizes. Are you sure you are not comparing > files shifted of a few bytes? One parameter of tiny_psnr is a shift between > the two files. Does > > tiny_psnr ~/ref_pod.wav ~/orig_pod.wav 2 10 > > Gives a much worse result? If the shift you are using now (zero) is correct, > changing it to anything else should make stddev much bigger. Can you also > put the wav files somewhere I can download? If you have a problem of quota, > you can use our FTP server as explained in [1]. >
Now that seems weird: $ ./tests/tiny_psnr ~/my_pod2.wav ~/orig_pod.wav 2 10 stddev: 2575.45 PSNR: 28.11 MAXDIFF:46172 bytes: 76480630/ 76480660 $ ./tests/tiny_psnr ~/my_pod2.wav ~/orig_pod.wav 2 -20 stddev: 2524.06 PSNR: 28.29 MAXDIFF:45328 bytes: 76480640/ 76480640 $ ./tests/tiny_psnr ~/my_pod2.wav ~/orig_pod.wav 2 200 stddev: 2090.99 PSNR: 29.92 MAXDIFF:46167 bytes: 76480440/ 76480660 I will upload the files later. Probably it will take some time. -- Marcelo _______________________________________________ FFmpeg-soc mailing list [email protected] https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-soc
