Add preamble value configuration for iec958 plugin

The preamble values can be defined in iec958 plugin configuration.
As default, Z/Y/X=8/4/2 is used.  CMI8338 has different values,
so override in its configuration.

diff --git a/src/conf/cards/CMI8338-SWIEC.conf b/src/conf/cards/CMI8338-SWIEC.conf
index 5e89505aee83ba0bf9aa47e944d48882d22e0bdc..d7ed2099873c36da5924dbfd1aec4e2144c8f680 100644 (file)
--- a/src/conf/cards/CMI8338-SWIEC.conf
+++ b/src/conf/cards/CMI8338-SWIEC.conf
@@ -95,6 +95,9 @@ CMI8338-SWIEC.pcm.iec958.0 {
                        device 2
                }
                status [ $AES0 $AES1 $AES2 $AES3 ]
+               preamble.z 3
+               preamble.y 5
+               preamble.x 9
        }
        capture.pcm {
                type hw

diff --git a/src/pcm/pcm_iec958.c b/src/pcm/pcm_iec958.c
index 23dd1b9783b3fb058d7a2f97f11af79372667b78..a87846c052203ba32fd682bc1fade22dcbbab4fb 100644 (file)
--- a/src/pcm/pcm_iec958.c
+++ b/src/pcm/pcm_iec958.c
@@ -59,8 +59,11 @@ struct snd_pcm_iec958 {
        unsigned int counter;
        unsigned char status[24];
        unsigned int byteswap;
+       unsigned char preamble[3];      /* B/M/W or Z/X/Y */
 };
 
+enum { PREAMBLE_Z, PREAMBLE_X, PREAMBLE_Y };
+
 #endif /* DOC_HIDDEN */
 
 /*
@@ -114,11 +117,11 @@ static inline u_int32_t iec958_subframe(snd_pcm_iec958_t *iec, u_int32_t data, i
 
        /* Preamble */
        if (! iec->counter)
-               data |= 0x03;           /* Block start, 'Z' */
+               data |= iec->preamble[PREAMBLE_Z];      /* Block start, 'Z' */
        else if (! channel)
-               data |= 0x05;           /* odd sub frame, 'Y' */
+               data |= iec->preamble[PREAMBLE_Y];      /* odd sub frame, 'Y' */
        else
-               data |= 0x09;           /* even sub frame, 'X' */
+               data |= iec->preamble[PREAMBLE_X];      /* even sub frame, 'X' */
 
        if (iec->byteswap)
                data = bswap_32(data);
@@ -437,7 +440,10 @@ static snd_pcm_ops_t snd_pcm_iec958_ops = {
  *          of compatibility reasons. The prototype might be freely
  *          changed in future.
  */           
-int snd_pcm_iec958_open(snd_pcm_t **pcmp, const char *name, snd_pcm_format_t sformat, snd_pcm_t *slave, int close_slave, const unsigned char *status_bits)
+int snd_pcm_iec958_open(snd_pcm_t **pcmp, const char *name, snd_pcm_format_t sformat,
+                       snd_pcm_t *slave, int close_slave,
+                       const unsigned char *status_bits,
+                       const unsigned char *preamble_vals)
 {
        snd_pcm_t *pcm;
        snd_pcm_iec958_t *iec;
@@ -473,6 +479,8 @@ int snd_pcm_iec958_open(snd_pcm_t **pcmp, const char *name, snd_pcm_format_t sfo
        else
                memcpy(iec->status, default_status_bits, sizeof(default_status_bits));
 
+       memcpy(iec->preamble, preamble_vals, 3);
+
        err = snd_pcm_new(&pcm, SND_PCM_TYPE_IEC958, name, slave->stream, slave->mode);
        if (err < 0) {
                free(iec);
@@ -508,6 +516,12 @@ pcm.name {
                 pcm { }         # Slave PCM definition
         }
        [status status-bytes]   # IEC958 status bits (given in byte array)
+       # IEC958 preamble bits definitions
+       # B/M/W or Z/X/Y, B = block start, M = even subframe, W = odd subframe
+       # As default, Z = 0x08, Y = 0x04, X = 0x02
+       [preamble.z or preamble.b val]
+       [preamble.x or preamble.m val]
+       [preamble.y or preamble.w val]
 }
 \endcode
 
@@ -541,9 +555,12 @@ int _snd_pcm_iec958_open(snd_pcm_t **pcmp, const char *name,
        int err;
        snd_pcm_t *spcm;
        snd_config_t *slave = NULL, *sconf;
-       snd_config_t *status = NULL;
+       snd_config_t *status = NULL, *preamble = NULL;
        snd_pcm_format_t sformat;
        unsigned char status_bits[24];
+       unsigned char preamble_vals[3] = {
+               0x08, 0x02, 0x04 /* Z, X, Y */
+       };
 
        snd_config_for_each(i, next, conf) {
                snd_config_t *n = snd_config_iterator_entry(i);
@@ -564,6 +581,14 @@ int _snd_pcm_iec958_open(snd_pcm_t **pcmp, const char *name,
                        status = n;
                        continue;
                }
+               if (strcmp(id, "preamble") == 0) {
+                       if (snd_config_get_type(n) != SND_CONFIG_TYPE_COMPOUND) {
+                               SNDERR("Invalid type for %s", id);
+                               return -EINVAL;
+                       }
+                       preamble = n;
+                       continue;
+               }
                SNDERR("Unknown field %s", id);
                return -EINVAL;
        }
@@ -590,6 +615,33 @@ int _snd_pcm_iec958_open(snd_pcm_t **pcmp, const char *name,
                }
                // fprintf(stderr, "STATUS bits: %02x %02x %02x %02x\n", status_bits[0], status_bits[1], status_bits[2], status_bits[3]);
        }
+       if (preamble) {
+               snd_config_iterator_t i, inext;
+               snd_config_for_each(i, inext, status) {
+                       long val;
+                       snd_config_t *n = snd_config_iterator_entry(i);
+                       const char *id;
+                       int idx;
+                       if (snd_config_get_id(n, &id) < 0)
+                               continue;
+                       if (strcmp(id, "b") == 0 || strcmp(id, "z") == 0)
+                               idx = PREAMBLE_Z;
+                       else if (strcmp(id, "m") == 0 || strcmp(id, "x") == 0)
+                               idx = PREAMBLE_X;
+                       else if (strcmp(id, "w") == 0 || strcmp(id, "y") == 0)
+                               idx = PREAMBLE_Y;
+                       else {
+                               SNDERR("invalid IEC958 preamble type %s", id);
+                               return -EINVAL;
+                       }
+                       err = snd_config_get_integer(n, &val);
+                       if (err < 0) {
+                               SNDERR("invalid IEC958 preamble value");
+                               return err;
+                       }
+                       preamble_vals[idx] = val;
+               }
+       }
        if (!slave) {
                SNDERR("slave is not defined");
                return -EINVAL;
@@ -609,7 +661,9 @@ int _snd_pcm_iec958_open(snd_pcm_t **pcmp, const char *name,
        snd_config_delete(sconf);
        if (err < 0)
                return err;
-       err = snd_pcm_iec958_open(pcmp, name, sformat, spcm, 1, status ? status_bits : NULL);
+       err = snd_pcm_iec958_open(pcmp, name, sformat, spcm, 1,
+                                 status ? status_bits : NULL,
+                                 preamble_vals);
        if (err < 0)
                snd_pcm_close(spcm);
        return err;