[igt-dev] [PATCH i-g-t 3/5] lib/igt_eld: parse Short Audio Descriptors

Simon Ser
2019-05-31T11:21:56Z

Each valid ELD entry can contain zero, one or more Short Audio Descriptor
blocks. These are exposed in sadN_* fields (N being the index of the SAD).

We need to parse them to be able to check that ALSA has properly processed
them.

Signed-off-by: Simon Ser <simon.ser@intel.com>
---
lib/igt_edid.h | 2 ++
lib/igt_eld.c | 85 +++++++++++++++++++++++++++++++++++++++++++++++++-
lib/igt_eld.h | 14 +++++++++
3 files changed, 100 insertions(+), 1 deletion(-)

diff --git a/lib/igt_edid.h b/lib/igt_edid.h
index 7edd7e38f41e..1d0c6aa29578 100644
--- a/lib/igt_edid.h
+++ b/lib/igt_edid.h
@@ -30,6 +30,8 @@

#include <stdint.h>

+#include <xf86drmMode.h>
+
struct est_timings {
uint8_t t1;
uint8_t t2;
diff --git a/lib/igt_eld.c b/lib/igt_eld.c
index a198001a56d7..732bbabd2d7c 100644
--- a/lib/igt_eld.c
+++ b/lib/igt_eld.c
@@ -35,6 +35,7 @@

#define ELD_PREFIX "eld#"
#define ELD_DELIM " \t"
+#define SAD_FMT "sad%d_%ms"

/**
* EDID-Like Data (ELD) is metadata parsed and exposed by ALSA for HDMI and
@@ -43,13 +44,87 @@
* on).
*/

+static enum cea_sad_format parse_sad_coding_type(const char *value)
+{
+ if (strcmp(value, "LPCM") == 0)
+ return CEA_SAD_FORMAT_PCM;
+ else
+ return 0;
+}
+
+static enum cea_sad_sampling_rate parse_sad_rate(const char *value)
+{
+ switch (atoi(value)) {
+ case 32000:
+ return CEA_SAD_SAMPLING_RATE_32KHZ;
+ case 44100:
+ return CEA_SAD_SAMPLING_RATE_44KHZ;
+ case 48000:
+ return CEA_SAD_SAMPLING_RATE_48KHZ;
+ case 88000:
+ return CEA_SAD_SAMPLING_RATE_88KHZ;
+ case 96000:
+ return CEA_SAD_SAMPLING_RATE_96KHZ;
+ case 176000:
+ return CEA_SAD_SAMPLING_RATE_176KHZ;
+ case 192000:
+ return CEA_SAD_SAMPLING_RATE_192KHZ;
+ default:
+ return 0;
+ }
+}
+
+static enum cea_sad_pcm_sample_size parse_sad_bit(const char *value)
+{
+ switch (atoi(value)) {
+ case 16:
+ return CEA_SAD_SAMPLE_SIZE_16;
+ case 20:
+ return CEA_SAD_SAMPLE_SIZE_20;
+ case 24:
+ return CEA_SAD_SAMPLE_SIZE_24;
+ default:
+ return 0;
+ }
+}
+
+static void parse_sad_field(struct eld_sad *sad, const char *key, char *value)
+{
+ char *tok;
+
+ /* Some fields are prefixed with the raw hex value, strip it */
+ if (value[0] == '[') {
+ value = strchr(value, ' ');
+ igt_assert(value != NULL);
+ value++; /* skip the space */
+ }
+
+ /* Single-value fields */
+ if (strcmp(key, "coding_type") == 0)
+ sad->coding_type = parse_sad_coding_type(value);
+ else if (strcmp(key, "channels") == 0)
+ sad->channels = atoi(value);
+
+ /* Multiple-value fields */
+ tok = strtok(value, " ");
+ while (tok) {
+ if (strcmp(key, "rates") == 0)
+ sad->rates |= parse_sad_rate(tok);
+ else if (strcmp(key, "bits") == 0)
+ sad->bits |= parse_sad_bit(tok);
+
+ tok = strtok(NULL, " ");
+ }
+}
+
static bool eld_parse_entry(const char *path, struct eld_entry *eld)
{
FILE *f;
char buf[1024];
- char *key, *value;
+ char *key, *value, *sad_key;
size_t len;
bool monitor_present;
+ int sad_index;

memset(eld, 0, sizeof(*eld));

@@ -76,6 +151,14 @@ static bool eld_parse_entry(const char *path, struct eld_entry *eld)
else if (strcmp(key, "monitor_name") == 0)
snprintf(eld->monitor_name, sizeof(eld->monitor_name),
"%s", value);
+ else if (strcmp(key, "sad_count") == 0)
+ eld->sads_len = atoi(value);
+ else if (sscanf(key, "sad%d_%ms", &sad_index, &sad_key) == 2) {
+ igt_assert(sad_index < ELD_SADS_CAP);
+ igt_assert(sad_index < eld->sads_len);
+ parse_sad_field(&eld->sads[sad_index], sad_key, value);
+ free(sad_key);
+ }
}

if (ferror(f) != 0) {
diff --git a/lib/igt_eld.h b/lib/igt_eld.h
index 21fe3537acf9..e16187884d4b 100644
--- a/lib/igt_eld.h
+++ b/lib/igt_eld.h
@@ -30,9 +30,23 @@

#include <stdbool.h>

+#include "igt_edid.h"
+
+#define ELD_SADS_CAP 4
+
+/** eld_sad: Short Audio Descriptor */
+struct eld_sad {
+ enum cea_sad_format coding_type;
+ int channels;
+ unsigned int rates; /* enum cea_sad_sampling_rate */
+ unsigned int bits; /* enum cea_sad_pcm_sample_size */
+};
+
struct eld_entry {
bool valid;
char monitor_name[16];
+ size_t sads_len;
+ struct eld_sad sads[ELD_SADS_CAP];
};

bool eld_has_igt(void);
--
2.21.0