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

Martin Peres
2019-06-03T12:57:21Z

On 31/05/2019 14:21, Simon Ser wrote:
> 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>
> +

Are you sure this change belongs to this commit? Can't find anything
here that would need this header.

> 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;

Poor key, why are you sad? :D

More seriously, a little documentation in this file about the acronyms
would be appreciated!

> 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);

Good that you added that! This patch looks good:

Reviewed-by: Martin Peres <martin.peres@linux.intel.com>

> + 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);