Re: [Rhythmbox-devel] playlist source burner

[Bastien Nocera <hadess hadess net>]

Replying to myself

On Sun, 2004-08-29 at 17:08 +0100, Bastien Nocera wrote:
> > The next thing is to determine how much space will be needed.  The 
> > easiest way is to compute it from the song duration.  Is it safe to rely 
> > on the duration being present and correct?
> 
> And then verify that the .wav files created still fit on the CD.

Some code I had around that does that.
Code is GPL, BTW.

---
Bastien Nocera <hadess hadess net> 
I have just watched The Big Blue on video but I couldn't see the
porpoise. -- reader Nibs Swenior

#include <glib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>

#include "acb-wave.h"

#define WAV_SIGNATURE_SIZE 16
#define LPCM_BITRATE (16 * 44.100 * 2)

/* From xine-lib, whoop */
typedef struct __attribute__((__packed__)) {
	gint16   wFormatTag;
	gint16   nChannels;
	gint32   nSamplesPerSec;
	gint32   nAvgBytesPerSec;
	gint16   nBlockAlign;
	gint16   wBitsPerSample;
	gint16   cbSize;
} waveformat;
#ifndef ATTRIBUTE_PACKED
#pragma pack()
#endif

/* Data from
 * http://www.onicos.com/staff/iz/formats/wav.html
 */
gint64
acb_wave_time (const char *filename)
{
	char buffer[WAV_SIGNATURE_SIZE];
	int fd, len;
	waveformat *wav;

	fd = open (filename, 0);
	if (fd < 0)
		return ACB_ERROR_OPEN;

	if (read (fd, buffer, WAV_SIGNATURE_SIZE) != WAV_SIGNATURE_SIZE)
		return ACB_ERROR_NOT_WAVE_TOO_SMALL;

	if ((buffer[0] != 'R') ||
	    (buffer[1] != 'I') ||
	    (buffer[2] != 'F') ||
	    (buffer[3] != 'F') ||
	    (buffer[8] != 'W') ||
	    (buffer[9] != 'A') ||
	    (buffer[10] != 'V') ||
	    (buffer[11] != 'E') ||
	    (buffer[12] != 'f') ||
	    (buffer[13] != 'm') ||
	    (buffer[14] != 't') ||
	    (buffer[15] != ' '))
		return -1;

	if (read (fd, &len, sizeof(len)) != sizeof (len))
	{
		close (fd);
		return ACB_ERROR_NOT_WAVE_TOO_SMALL;
	}
	if (GINT_TO_LE (len) != 16)
	{
		close (fd);
		g_print ("file len not defined\n");
		return ACB_ERROR_NOT_WAVE_FORMAT;
	}

	wav = g_malloc (len);
	if (read (fd, wav, len) != len)
	{
		g_free (wav);
		close (fd);
		return ACB_ERROR_NOT_WAVE_FILE;
	}

	close (fd);

	if (wav->nChannels != 2
			|| wav->nSamplesPerSec != 44100
			|| wav->wBitsPerSample != 16)
	{
		g_free (wav);
		return ACB_ERROR_NOT_WAVE_FORMAT;
	}

	g_free (wav);

	{
		struct stat buf;

		if (stat (filename, &buf) != 0)
			return ACB_ERROR_OPEN;

		return buf.st_size * 8 / LPCM_BITRATE;
	}
}

#define ACB_ERROR_OPEN				-1
#define ACB_ERROR_NOT_WAVE_TOO_SMALL		-2
#define ACB_ERROR_NOT_WAVE_FILE			-3
#define ACB_ERROR_NOT_WAVE_FORMAT		-4

gint64 acb_wave_time (const char *filename);