libgsmhr1 TFO: require BFI=0 and SID=0 for homing In order for a received frame to be recognized as DHF, we need not only the correct bit pattern, but also BFI=0 and SID=0. The BFI=0 requirement should be obvious, while the SID=0 requirement is needed only for HR codec. With FR and EFR, SID classification comes from the payload bits and no separate check is needed - but in HR we get an out-of-band SID ternary flag. When SID=1, no payload bits are used at all; when SID=2, we use only the first 33 bits of the payload. Therefore, it is proper to conditionalize DHF acceptance on SID=0. We already implemented this logic in the just finished full decoder; now bring TFO code into agreement.

/*
 * Here we implement our PCM write helper function.
 */

#include <stdint.h>
#include "wavwriter.h"
#include "pcmwrite.h"

void write_pcm_to_wav(void *wav, const int16_t *pcm)
{
	uint8_t bytes[320], *dp;
	int16_t samp;
	unsigned n;

	dp = bytes;
	for (n = 0; n < 160; n++) {
		samp = pcm[n];
		*dp++ = samp & 0xFF;
		*dp++ = (samp >> 8) & 0xFF;
	}
	wav_write_data(wav, bytes, 320);
}