[PATCHv6 2/5] hdmi: added functions for MPEG InfoFrames
Enric Balletbo i Serra
eballetbo at gmail.com
Fri Dec 4 00:35:04 PST 2015
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 <enric.balletbo at collabora.com>
---
Changes since last version (requested by Thierry Redding)
- hdmi_infoframe_pack: Fix missing break
- hdmi_mpeg_picture_get_name: return NULL instead of "Reserved"
- hdmi_mpeg_picture_get_name: use more canonical names "I-Frame", "P-Frame", etc
- hdmi_mpeg_infoframe_unpack: remove braces that aren't needed
- hdmi_vendor_any_infoframe: s/mpeg/MPEG/
drivers/video/hdmi.c | 156 +++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/hdmi.h | 24 ++++++++
2 files changed, 180 insertions(+)
diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c
index 1626892..47121a6 100644
--- a/drivers/video/hdmi.c
+++ b/drivers/video/hdmi.c
@@ -388,6 +388,81 @@ ssize_t hdmi_vendor_infoframe_pack(struct hdmi_vendor_infoframe *frame,
}
EXPORT_SYMBOL(hdmi_vendor_infoframe_pack);
+/**
+ * hdmi_mpeg_infoframe_init() - initialize an HDMI MPEG infoframe
+ * @frame: HDMI MPEG infoframe
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+int hdmi_mpeg_infoframe_init(struct hdmi_mpeg_infoframe *frame)
+{
+ memset(frame, 0, sizeof(*frame));
+
+ frame->type = HDMI_INFOFRAME_TYPE_MPEG;
+ frame->version = 1;
+ frame->length = HDMI_MPEG_INFOFRAME_SIZE;
+
+ return 0;
+}
+EXPORT_SYMBOL(hdmi_mpeg_infoframe_init);
+
+/**
+ * hdmi_mpeg_infoframe_pack() - write HDMI MPEG infoframe to binary buffer
+ * @frame: HDMI MPEG infoframe
+ * @buffer: destination buffer
+ * @size: size of buffer
+ *
+ * Packs the information contained in the @frame structure into a binary
+ * representation that can be written into the corresponding controller
+ * registers. Also computes the checksum as required by section 5.3.5 of
+ * the HDMI 1.4 specification.
+ *
+ * Returns the number of bytes packed into the binary buffer or a negative
+ * error code on failure.
+ */
+ssize_t hdmi_mpeg_infoframe_pack(struct hdmi_mpeg_infoframe *frame,
+ void *buffer, size_t size)
+{
+ u8 *ptr = buffer;
+ size_t length;
+
+ length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
+
+ if (size < length)
+ return -ENOSPC;
+
+ memset(buffer, 0, size);
+
+ ptr[0] = frame->type;
+ ptr[1] = frame->version;
+ ptr[2] = frame->length;
+ ptr[3] = 0; /* checksum */
+
+ /* start infoframe payload */
+ ptr += HDMI_INFOFRAME_HEADER_SIZE;
+
+ /*
+ * The MPEG Bit Rate is stored as a 32-bit number and is expressed in
+ * Hertz. MB#0 contains the least significant byte while MB#3 contains
+ * the most significant byte. If the MPEG Bit Rate is unknown or this
+ * field doesn’t apply, then all of the bits in Data Bytes 1-4 shall
+ * be set to 0.
+ */
+ ptr[0] = frame->bitrate & 0x000000ff;
+ ptr[1] = (frame->bitrate & 0x0000ff00) >> 8;
+ ptr[2] = (frame->bitrate & 0x00ff0000) >> 16;
+ ptr[3] = (frame->bitrate & 0xff000000) >> 24;
+
+ ptr[4] = frame->frame_type;
+ if (frame->repeated)
+ ptr[4] |= BIT(4);
+
+ hdmi_infoframe_set_checksum(buffer, length);
+
+ return length;
+}
+EXPORT_SYMBOL(hdmi_mpeg_infoframe_pack);
+
/*
* hdmi_vendor_any_infoframe_pack() - write a vendor infoframe to binary buffer
*/
@@ -435,6 +510,9 @@ 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);
+ break;
default:
WARN(1, "Bad infoframe type %d\n", frame->any.type);
length = -EINVAL;
@@ -457,6 +535,8 @@ static const char *hdmi_infoframe_type_get_name(enum hdmi_infoframe_type type)
return "Source Product Description (SPD)";
case HDMI_INFOFRAME_TYPE_AUDIO:
return "Audio";
+ case HDMI_INFOFRAME_TYPE_MPEG:
+ return "MPEG";
}
return "Reserved";
}
@@ -899,6 +979,41 @@ 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_frame_type type)
+{
+ switch (type) {
+ case HDMI_MPEG_UNKNOWN_FRAME:
+ return "Unknown";
+ case HDMI_MPEG_I_FRAME:
+ return "Intra-coded picture";
+ case HDMI_MPEG_B_FRAME:
+ return "Bi-predictive picture";
+ case HDMI_MPEG_P_FRAME:
+ return "Predicted picture";
+ }
+ return NULL;
+}
+
+/**
+ * hdmi_mpeg_infoframe_log() - log info of HDMI MPEG infoframe
+ * @level: logging level
+ * @dev: device
+ * @frame: HDMI MPEG infoframe
+ */
+static void hdmi_mpeg_infoframe_log(const char *level,
+ struct device *dev,
+ struct hdmi_mpeg_infoframe *frame)
+{
+ hdmi_infoframe_log_header(level, dev,
+ (struct hdmi_any_infoframe *)frame);
+
+ hdmi_log(" bit rate: %d Hz\n", frame->bitrate);
+ hdmi_log(" frame type: %s\n",
+ hdmi_mpeg_picture_get_name(frame->frame_type));
+ hdmi_log(" repeated frame: %s\n",
+ frame->repeated ? "Yes" : "No");
+}
+
static const char *
hdmi_3d_structure_get_name(enum hdmi_3d_structure s3d_struct)
{
@@ -987,6 +1102,9 @@ void hdmi_infoframe_log(const char *level,
case HDMI_INFOFRAME_TYPE_VENDOR:
hdmi_vendor_any_infoframe_log(level, dev, &frame->vendor);
break;
+ case HDMI_INFOFRAME_TYPE_MPEG:
+ hdmi_mpeg_infoframe_log(level, dev, &frame->mpeg);
+ break;
}
}
EXPORT_SYMBOL(hdmi_infoframe_log);
@@ -1138,6 +1256,41 @@ static int hdmi_audio_infoframe_unpack(struct hdmi_audio_infoframe *frame,
}
/**
+ * hdmi_mpeg_infoframe_unpack() - unpack binary buffer to a HDMI MPEG infoframe
+ * @buffer: source buffer
+ * @frame: HDMI MPEG infoframe
+ *
+ * Unpacks the information contained in binary @buffer into a structured
+ * @frame of the HDMI MPEG information frame. Also verifies the checksum as
+ * required by section 5.3.5 of the HDMI 1.4 specification.
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+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;
+
+ if (hdmi_infoframe_checksum(buffer, HDMI_INFOFRAME_SIZE(MPEG)) != 0)
+ return -EINVAL;
+
+ ptr += HDMI_INFOFRAME_HEADER_SIZE;
+
+ frame->bitrate = (ptr[3] << 24) | (ptr[2] << 16) |
+ (ptr[1] << 8) | ptr[0];
+
+ frame->frame_type = ptr[4] & 0x03;
+ frame->repeated = ptr[4] & BIT(4) ? true : false;
+
+ return 0;
+}
+
+/**
* hdmi_vendor_infoframe_unpack() - unpack binary buffer to a HDMI vendor infoframe
* @buffer: source buffer
* @frame: HDMI Vendor infoframe
@@ -1234,6 +1387,9 @@ int hdmi_infoframe_unpack(union hdmi_infoframe *frame, void *buffer)
case HDMI_INFOFRAME_TYPE_VENDOR:
ret = hdmi_vendor_any_infoframe_unpack(&frame->vendor, buffer);
break;
+ case HDMI_INFOFRAME_TYPE_MPEG:
+ ret = hdmi_mpeg_infoframe_unpack(&frame->mpeg, buffer);
+ break;
default:
ret = -EINVAL;
break;
diff --git a/include/linux/hdmi.h b/include/linux/hdmi.h
index e974420..c033554 100644
--- a/include/linux/hdmi.h
+++ b/include/linux/hdmi.h
@@ -32,11 +32,13 @@ enum hdmi_infoframe_type {
HDMI_INFOFRAME_TYPE_AVI = 0x82,
HDMI_INFOFRAME_TYPE_SPD = 0x83,
HDMI_INFOFRAME_TYPE_AUDIO = 0x84,
+ HDMI_INFOFRAME_TYPE_MPEG = 0x85,
};
#define HDMI_IEEE_OUI 0x000c03
#define HDMI_INFOFRAME_HEADER_SIZE 4
#define HDMI_AVI_INFOFRAME_SIZE 13
+#define HDMI_MPEG_INFOFRAME_SIZE 10
#define HDMI_SPD_INFOFRAME_SIZE 25
#define HDMI_AUDIO_INFOFRAME_SIZE 10
@@ -297,6 +299,26 @@ int hdmi_vendor_infoframe_init(struct hdmi_vendor_infoframe *frame);
ssize_t hdmi_vendor_infoframe_pack(struct hdmi_vendor_infoframe *frame,
void *buffer, size_t size);
+enum hdmi_mpeg_frame_type {
+ HDMI_MPEG_UNKNOWN_FRAME = 0x00,
+ HDMI_MPEG_I_FRAME = 0x01,
+ HDMI_MPEG_B_FRAME = 0x02,
+ HDMI_MPEG_P_FRAME = 0x03,
+};
+
+struct hdmi_mpeg_infoframe {
+ enum hdmi_infoframe_type type;
+ unsigned char version;
+ unsigned char length;
+ u32 bitrate;
+ enum hdmi_mpeg_frame_type frame_type;
+ bool repeated;
+};
+
+int hdmi_mpeg_infoframe_init(struct hdmi_mpeg_infoframe *frame);
+ssize_t hdmi_mpeg_infoframe_pack(struct hdmi_mpeg_infoframe *frame,
+ void *buffer, size_t size);
+
union hdmi_vendor_any_infoframe {
struct {
enum hdmi_infoframe_type type;
@@ -314,6 +336,7 @@ union hdmi_vendor_any_infoframe {
* @spd: spd infoframe
* @vendor: union of all vendor infoframes
* @audio: audio infoframe
+ * @mpeg: MPEG infoframe
*
* This is used by the generic pack function. This works since all infoframes
* have the same header which also indicates which type of infoframe should be
@@ -325,6 +348,7 @@ union hdmi_infoframe {
struct hdmi_spd_infoframe spd;
union hdmi_vendor_any_infoframe vendor;
struct hdmi_audio_infoframe audio;
+ struct hdmi_mpeg_infoframe mpeg;
};
ssize_t
--
2.1.0
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