On Sat, Nov 14, 2015 at 07:38:19PM +0100, Enric Balletbo i Serra wrote:
The MPEG Source (MS) InfoFrame is in EIA/CEA-861B. It describes aspects of
the compressed video stream that were used to produce the uncompressed
video.
The patch adds functions to work with MPEG InfoFrames.
Signed-off-by: Enric Balletbo i Serra <redacted>
---
drivers/video/hdmi.c | 156 +++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/hdmi.h | 24 ++++++++
2 files changed, 180 insertions(+)
According to the CEA specification a source is expected to send this
type of infoframe once per video frame. I'm curious how you envision
this to be ensured. Would hardware provide a mechanism to store this
data and send the infoframe automatically? How would you ensure that
updates sent to the hardware match the upcoming frame?
quoted hunk ↗ jump to hunk
diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c
[...]
quoted hunk ↗ jump to hunk
@@ -435,6 +510,8 @@ hdmi_infoframe_pack(union hdmi_infoframe *frame, void *buffer, size_t size)
length = hdmi_vendor_any_infoframe_pack(&frame->vendor,
buffer, size);
break;
+ case HDMI_INFOFRAME_TYPE_MPEG:
+ length = hdmi_mpeg_infoframe_pack(&frame->mpeg, buffer, size);
Missing "break;"?
quoted hunk ↗ jump to hunk
@@ -899,6 +978,41 @@ static void hdmi_audio_infoframe_log(const char *level,
frame->downmix_inhibit ? "Yes" : "No");
}
+static const char *hdmi_mpeg_picture_get_name(enum hdmi_mpeg_picture_type type)
+{
+ switch (type) {
+ case HDMI_MPEG_PICTURE_TYPE_UNKNOWN:
+ return "Unknown";
+ case HDMI_MPEG_PICTURE_TYPE_I:
+ return "Intra-coded picture";
+ case HDMI_MPEG_PICTURE_TYPE_B:
+ return "Bi-predictive picture";
+ case HDMI_MPEG_PICTURE_TYPE_P:
+ return "Predicted picture";
+ }
I'd have chosen the slightly more canonical "I-Frame", "P-Frame",
"B-Frame" here, but that's not a strong objection.
+ return "Reserved";
There really can't be another value here, so I think this should either
return NULL or even go as far as let it crash. There should be no way
for the invalid value to make it this far.
quoted hunk ↗ jump to hunk
+static int hdmi_mpeg_infoframe_unpack(struct hdmi_mpeg_infoframe *frame,
+ void *buffer)
+{
+ u8 *ptr = buffer;
+
+ if (ptr[0] != HDMI_INFOFRAME_TYPE_MPEG ||
+ ptr[1] != 1 ||
+ ptr[2] != HDMI_MPEG_INFOFRAME_SIZE) {
+ return -EINVAL;
+ }
There's no need for the braces here.
quoted hunk ↗ jump to hunk
@@ -314,6 +336,7 @@ union hdmi_vendor_any_infoframe {
* @spd: spd infoframe
* @vendor: union of all vendor infoframes
* @audio: audio infoframe
+ * @mpeg: mpeg infoframe
s/mpeg/MPEG/
Thierry