similar to: new SEEKTABLE block

I first thought that it would be much better to create a single seek standard for FLAC. Then, I thought, why couldn't someone just create the optional SEEKTABLE data after an initial encode, if they need this data? Since the checksums are a part of the FLAC format (unlike Shorten), and these checksums are on the data stream, not the metadata, so any additional metadata shouldn't matter or

On my lists of things to do for 1.0 were 1) improve seeking; and 2) speed up both encoding and decoding. Seeking seems better now (I added the SEEKTABLE and tweaked the search algorithm). On the way, one of my encoding experiments worked. By taking advantage of a relatively unused area in the Rice parameter space, I added an escape code for switching to flat encoding within a partition.

Op zo 13 okt 2024 om 02:16 schreef Stefan Oltmanns <stefan-oltmanns at gmx.net>: > > I cannot find any clues in the documentation how to write a > seektable/reserve space for it. > Can someone help me out? > There's actually quite a lot of documentation for this. Please review https://xiph.org/flac/api/group__flac__stream__encoder.html#ga80d57f9069e354cbf1a15a3e3ad9ca78

Op zo 13 okt 2024 om 22:33 schreef Stefan Oltmanns <stefan-oltmanns at gmx.net>: > > Is the seektable written at the beginning of the file in the metadata > block or can there also be a second metadata block at the end? > Only at the start of the file. > > If it's at the beginning, would it possible to reserve space for N seek > points and during encoding remember

Hi Martijn, Am 13.10.24 um 21:00 schrieb Martijn van Beurden: > > There's actually quite a lot of documentation for this. > > Please review https://xiph.org/flac/api/group__flac__stream__encoder.html#ga80d57f9069e354cbf1a15a3e3ad9ca78 > > I quote: >> SEEKTABLE blocks are handled specially. Since you will not know the >> values for the seek point stream offsets,

Am 14.10.24 um 09:11 schrieb Martijn van Beurden: > Op zo 13 okt 2024 om 22:33 schreef Stefan Oltmanns <stefan-oltmanns at gmx.net>: >> > >> >> The signal is the FM-modulated video signal of video tapes (like VHS). >> The idea is to capture the signal directly from the video head amplifier >> in the VCR and later demodulate/decode it in software, providing

This is a fantastic selling point, and one that I've never really thought of. Back in the early days of etree (a whole three years ago ;) ), before we learned the virtues of MD5 sums for SHN downloads, I downloaded a Hornsby show from someone. Of course, an MD5 wasn't available, but when I decompressed and Shoren didn't throw a sanity error my way, I figured all was well. I burned

Hello, I'm using flac to compress s signal data during capture. The sample rate is almost a thousands time higher compared to audio (40 MHz), resulting in a lot of data very quickly. I'm using the C API in my capturing application (mostly copy&paste directly from the example) and it works so far, but unfortunately for longer captures there is no seeking information. How can I tell

I think there is another major issue for me: In METADATA_BLOCK_STREAMINFO the field for the length is only 36 bit, that's not even half an hour at 40 MHz sample rate, resulting in that the encoder sets it to 0 for longer captures. In the seekpoint the sample number is 64 bit, which is more than enough. But how does the decoder handle the seektable when the total number of samples is unknown?

Op ma 14 okt 2024 om 16:06 schreef Stefan Oltmanns <stefan-oltmanns at gmx.net>: > > Unfortunately that doesn't seem to be the case. I just made a capture > that is > 30 Minutes with total samples set to 0 and a seek table: All > players I tried cannot seek in the file and cannot determine it's > length: VLC, Celluloid and DeaDBeef > > I wondered why I can

Op wo 16 okt 2024 om 16:25 schreef Stefan Oltmanns <stefan-oltmanns at gmx.net>: > > Yes, overwriting the streaminfo total_samples number is a bit of a hack, > but it would only affect those files with more than 2^36 samples that > contains the special seek point, so no difference for the average flac user. > > Not sure how the applications actually read flac files, if they

Am 16.10.24 um 15:15 schrieb Martijn van Beurden: > > But how should such a number be presented to the libFLAC user? You > suggested overwriting the streaminfo total_samples number, but > streaminfo always precedes the seektable, so the streaminfo metadata > block is already parsed by the application before the seektable is > even read. Also, I think it is quite hacky to not pass

Please excuse me, I haven't yet dug into the code too far. What I'd like to do: I'm using ecasound to record for 24 hour periods, which pipes the output directly to flac. I would like to be able to decode sections of this (using until/skip) during recording/encoding. I understand currently that flac can't do this, unless I pipe into dd to skip after decoding (which would be an

I have read FLAC's "--help", the man-page, and the HTML documentaion, but there are a few things that I don't understand. 1. I'll start with the thing I'm most confused about. The --best option is synonymous with -l 12 -b 4608 -m -e -r 6. Why is that? Is not -l 32 better that l- 12? And you can have -r 0,8 without using --lax, and -r 0,16 with --lax. 2. The --lax option

Hi! I've been using a little C++ program I've written to encode flac files. The program does this in the usual way (I think), by inheriting a class from FLAC::Encoder::File, and passing it chunks of raw samples through process_interleaved()... Anyway, the program works beautifully, and I've now decided to try and add some metadata to the encoded flacs. Eventually, there will be vorbis

On Wed, 16 Oct 2024 at 00:18, Stefan Oltmanns <stefan-oltmanns at gmx.net> wrote: > Am 15.10.24 um 21:26 schrieb Alistair Buxton: > > Another SDR user here. It was me who reported the bug where total samples > > wraps around on overflow. > > That's a bug in the flac application. I think the correct behavior is > setting it to 0 if total samples > 2^36 >

Op di 15 okt 2024 om 21:27 schreef Alistair Buxton <a.j.buxton at gmail.com>: > > I would like to see this kind of thing put into a secondary metadata block aimed specifically at SDR. This could be completely ignored by regular audio players - these files are not meant to be listened to anyway. I could probably figure out how to implement that, I even started looking into it once, but

Ok, the patch from 2003 about improving seeking still didn't make it to CVS, so here is another try. I made some benchmarking with the test_seeking utility from flac sources to show how bad the current seeking is, especially without seektable. Track used for the experiment had about 50 minutes. In the following table is average number of seeks and number of decoded frames required for one

Am 15.10.24 um 21:26 schrieb Alistair Buxton: > Another SDR user here. It was me who reported the bug where total samples > wraps around on overflow. That's a bug in the flac application. I think the correct behavior is setting it to 0 if total samples > 2^36 > > FLAC performs extremely well on SDR samples, both speed and compression > ratio. In my testing it outperforms

As far as I can tell I've found a serious bug in the command line flac encoder :( I have created many hundreds of flac files and I was very annoyed to discover that the XMMS flac plug-in had intolerably long seek times, but since that had been mentioned on this list a bunch of times without anyone actually investigating, I thought I had better actually find the BUG which causes this. 1. I