LTCWRITE_TEMPLATE functions broken

[jalexstark]

These do not work for buffers over 1024 samples, because they copy the first bytes in the input buffer repeatedly into the ltc write buffer. Here is suggested code for ltc.c:

#define CONVERSION_BUF_SIZE 1024

#define LTCWRITE_TEMPLATE(FN, FORMAT, CONV) \
void ltc_decoder_write_ ## FN (LTCDecoder *d, FORMAT *buf, size_t size, ltc_off_t posinfo) { \
        ltcsnd_sample_t tmp[CONVERSION_BUF_SIZE]; \
        size_t copyStart = 0; \
        while (copyStart < size) { \
                int c = size - copyStart; \
                c = (c > CONVERSION_BUF_SIZE) ? CONVERSION_BUF_SIZE : c; \
                int i; \
                for (i=0; i<c; i++) { \
                        tmp[i] = CONV; \
                } \
                decode_ltc(d, tmp, c, posinfo + (ltc_off_t)c); \
                copyStart += c; \
        } \
}

LTCWRITE_TEMPLATE(float, float, 128 + (buf[copyStart+i] * 127.0))
/* this relies on the compiler to use an arithemtic right-shift for signed values */
LTCWRITE_TEMPLATE(s16, short, 128 + (buf[copyStart+i] >> 8))
/* this relies on the compiler to use a logical right-shift for unsigned values */
LTCWRITE_TEMPLATE(u16, unsigned short, (buf[copyStart+i] >> 8))

[jalexstark]

Actually, there were two consequences of the bug. The following fixes the offsets as well.

#define CONVERSION_BUF_SIZE 1024

#define LTCWRITE_TEMPLATE(FN, FORMAT, CONV) \
void ltc_decoder_write_ ## FN (LTCDecoder *d, FORMAT *buf, size_t size, ltc_off_t posinfo) { \
        ltcsnd_sample_t tmp[CONVERSION_BUF_SIZE]; \
        size_t copyStart = 0; \
        while (copyStart < size) { \
                int c = size - copyStart; \
                c = (c > CONVERSION_BUF_SIZE) ? CONVERSION_BUF_SIZE : c; \
                int i; \
                for (i=0; i<c; i++) { \
                        tmp[i] = CONV; \
                } \
                decode_ltc(d, tmp, c, posinfo + (ltc_off_t)copyStart); \
                copyStart += c; \
        } \
}

LTCWRITE_TEMPLATE(float, float, 128 + (buf[copyStart+i] * 127.0))
/* this relies on the compiler to use an arithemtic right-shift for signed values */
LTCWRITE_TEMPLATE(s16, short, 128 + (buf[copyStart+i] >> 8))
/* this relies on the compiler to use a logical right-shift for unsigned values */
LTCWRITE_TEMPLATE(u16, unsigned short, (buf[copyStart+i] >> 8))

[x42]

Could you please post a diff (or file a pull request)- also for issue #7. That'll make it much more obvious and allow to comment on the changes. thanks.