It depends what you mean by "standard".ocenaudio wrote:Do you know any RIFF metadata standard (like ID3)?tommy_d wrote:1. Does it support RIFF metadata (i.e. markers & loop points within the .wav file)? Do cues and regions correspond to marker metadata, or are they external to the audio file itself? How do you insert a cue?
As I understand it, the original specification allows for all kinds of metadata, including:
* a cue-points chunk <cue-ck>. Each cue point has six fields, including one for the name ("dwName"). (I'm paraphrasing section 3-27, page 61 of "Multimedia Programming Interface and Data Specifications 1.0", IBM Corporation and Microsoft Corporation, August 1991 which is available here).
* a playlist chunk <playlist-ck>, the <play-segment> of which includes a field for the length of the section in samples ("dwLength") and a field specifying the number of times to play the section ("wLoops"). (Section 3-29, page 63 of the same document).
* an associated data list, which includes a label chunk and a note chunk. The label chunk <labl-ck> allows you to name the cue points identified in <cue-ck>; the note chunk <note-ck> allows you to attach text/comments to them. (Sections 3-29 & 3-30, pages 63 & 64).
...However, the extent to which these aspects of the specification are implemented by different applications is anything but "standardised", as far as I can see
(I've posted about this before, both on KVR and elsewhere).It's not an idle enquiry. I'm asking about markers and loop points for three reasons (apologies in advance for a long post!):
1. I've got a portable recorder (a Zoon H4n) that I use for making live and field recordings. Pressing the record button during recording inserts a marker into the file. Which can be very useful later if you want to find one particular bit of an hour-long recording. Unfortunately, not all audio editors recognise these markers!
2. Many software samplers have some kind of built-in waveform display that allows you to set the "start loop" and "end loop" points of a sample. But it's often easier to do this kind of thing with a dedicated audio editor (better display, ability to zoom in, better file handling etc.). (For instance, you can use Wavosaur to insert loop points in .wav files and sfz player will recognise them). Not all audio editors allow you to do this.
3. The ability to insert named markers in files and use them as "signposts" can be very useful...but only if applications recognise them, of course. For instance:
A colleague sent me some audio files of guide recordings and asked me to add my contributions. Which I did...but I also changed the structure. So when I sent the files of my parts back to him, I embedded labeled markers to identify where the different sections ("1. Intro", "2. V1", "3. Cs1" etc.) now began. I thought I was being helpful, and it's simple to do using Reaper, but it didn't work. I assumed - naively, as it turned out - that his host (Nuendo) would be able to identify the markers, even if it couldn't read the labels. But I was wrong: Nuendo, it seems, can't even do that
(see here)A free cross-platform audio editor that features a thorough implementation of the metadata provisions of the .wav spec would be a thing to behold. Seriously.
