return lrint(rate * speed);
}
// Return the format libavresample should convert to, given the final output
// format mp_format. In some cases (S24) we perform an extra conversion step,
// and signal here what exactly libavresample should output. It will be the
// input to the final conversion to mp_format.
static int check_output_conversion(int mp_format)
{
if (mp_format == AF_FORMAT_S24)
return AV_SAMPLE_FMT_S32;
return af_to_avformat(mp_format);
}
static struct mp_chmap fudge_pairs[][2] = {
{MP_CHMAP2(BL, BR), MP_CHMAP2(SL, SR)},
{MP_CHMAP2(SL, SR), MP_CHMAP2(BL, BR)},
{MP_CHMAP2(SDL, SDR), MP_CHMAP2(SL, SR)},
{MP_CHMAP2(SL, SR), MP_CHMAP2(SDL, SDR)},
};
// Modify out_layout and return the new value. The intention is reducing the
// loss libswresample's rematrixing will cause by exchanging similar, but
// strictly speaking incompatible channel pairs. For example, 7.1 should be
// changed to 7.1(wide) without dropping the SL/SR channels. (We still leave
// it to libswresample to create the remix matrix.)
static uint64_t fudge_layout_conversion(struct af_instance *af,
uint64_t in, uint64_t out)
{
for (int n = 0; n < MP_ARRAY_SIZE(fudge_pairs); n++) {
uint64_t a = mp_chmap_to_lavc(&fudge_pairs[n][0]);
p->delay -= delta * (int)(p->par.bps * p->par.pchan);
}
/*
* call-back invoked to notify about volume changes
*/
static void volcb(void *addr, unsigned newvol)
{
struct priv *p = addr;
p->vol = newvol;
}
static const struct mp_chmap sndio_layouts[MP_NUM_CHANNELS + 1] = {
{0}, // empty
{1, {MP_SPEAKER_ID_FL}}, // mono
MP_CHMAP2(FL, FR), // stereo
{0}, // 2.1
MP_CHMAP4(FL, FR, BL, BR), // 4.0
{0}, // 5.0
MP_CHMAP6(FL, FR, BL, BR, FC, LFE), // 5.1
{0}, // 6.1
MP_CHMAP8(FL, FR, BL, BR, FC, LFE, SL, SR), // 7.1
/* above is the fixed channel assignment for sndio, since we need to fill
all channels and cannot insert silence, not all layouts are supported. */
};
/*
* open device and setup parameters
* return: 0=success -1=fail
*/
static int init(struct ao *ao)
