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authorMirela Rabulea <mirela.rabulea@nxp.com>2021-03-11 01:28:49 +0100
committerMauro Carvalho Chehab <mchehab+huawei@kernel.org>2021-03-22 10:35:36 +0100
commitb8035f7988a82cbbabf1009b9f3234ff2431f8a4 (patch)
tree12c697ac478db28d673d4d98fdbd08790ca49d8b
parentmedia: dt-bindings: Add bindings for i.MX8QXP/QM JPEG driver (diff)
downloadlinux-dev-b8035f7988a82cbbabf1009b9f3234ff2431f8a4.tar.xz
linux-dev-b8035f7988a82cbbabf1009b9f3234ff2431f8a4.zip
media: Add parsing for APP14 data segment in jpeg helpers
According to Rec. ITU-T T.872 (06/2012) 6.5.3 APP14 segment is for color encoding, it contains a transform flag, which may have values of 0, 1 and 2 and are interpreted as follows: 0 - CMYK for images that are encoded with four components - RGB for images that are encoded with three components 1 - An image encoded with three components using YCbCr colour encoding. 2 - An image encoded with four components using YCCK colour encoding. This is used in imx-jpeg decoder, to distinguish between YUV444 and RGB24. Signed-off-by: Mirela Rabulea <mirela.rabulea@nxp.com> Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
-rw-r--r--drivers/media/v4l2-core/v4l2-jpeg.c42
-rw-r--r--include/media/v4l2-jpeg.h20
2 files changed, 61 insertions, 1 deletions
diff --git a/drivers/media/v4l2-core/v4l2-jpeg.c b/drivers/media/v4l2-core/v4l2-jpeg.c
index 9071b6cc6d0e..ede40f2a5456 100644
--- a/drivers/media/v4l2-core/v4l2-jpeg.c
+++ b/drivers/media/v4l2-core/v4l2-jpeg.c
@@ -45,6 +45,7 @@ MODULE_LICENSE("GPL");
#define DHP 0xffde /* hierarchical progression */
#define EXP 0xffdf /* expand reference */
#define APP0 0xffe0 /* application data */
+#define APP14 0xffee /* application data for colour encoding */
#define APP15 0xffef
#define JPG0 0xfff0 /* extensions */
#define JPG13 0xfffd
@@ -444,6 +445,39 @@ static int jpeg_skip_segment(struct jpeg_stream *stream)
return jpeg_skip(stream, len - 2);
}
+/* Rec. ITU-T T.872 (06/2012) 6.5.3 */
+static int jpeg_parse_app14_data(struct jpeg_stream *stream,
+ enum v4l2_jpeg_app14_tf *tf)
+{
+ int ret;
+ int lp;
+ int skip;
+
+ lp = jpeg_get_word_be(stream);
+ if (lp < 0)
+ return lp;
+
+ /* Check for "Adobe\0" in Ap1..6 */
+ if (stream->curr + 6 > stream->end ||
+ strncmp(stream->curr, "Adobe\0", 6))
+ return -EINVAL;
+
+ /* get to Ap12 */
+ ret = jpeg_skip(stream, 11);
+ if (ret < 0)
+ return ret;
+
+ ret = jpeg_get_byte(stream);
+ if (ret < 0)
+ return ret;
+
+ *tf = ret;
+
+ /* skip the rest of the segment, this ensures at least it is complete */
+ skip = lp - 2 - 11;
+ return jpeg_skip(stream, skip);
+}
+
/**
* v4l2_jpeg_parse_header - locate marker segments and optionally parse headers
* @buf: address of the JPEG buffer, should start with a SOI marker
@@ -476,6 +510,9 @@ int v4l2_jpeg_parse_header(void *buf, size_t len, struct v4l2_jpeg_header *out)
if (marker != SOI)
return -EINVAL;
+ /* init value to signal if this marker is not present */
+ out->app14_tf = V4L2_JPEG_APP14_TF_UNKNOWN;
+
/* loop through marker segments */
while ((marker = jpeg_next_marker(&stream)) >= 0) {
switch (marker) {
@@ -519,7 +556,10 @@ int v4l2_jpeg_parse_header(void *buf, size_t len, struct v4l2_jpeg_header *out)
ret = jpeg_parse_restart_interval(&stream,
&out->restart_interval);
break;
-
+ case APP14:
+ ret = jpeg_parse_app14_data(&stream,
+ &out->app14_tf);
+ break;
case SOS:
ret = jpeg_reference_segment(&stream, &out->sos);
if (ret < 0)
diff --git a/include/media/v4l2-jpeg.h b/include/media/v4l2-jpeg.h
index 3a3344a97678..2dba843ce3bd 100644
--- a/include/media/v4l2-jpeg.h
+++ b/include/media/v4l2-jpeg.h
@@ -88,6 +88,24 @@ struct v4l2_jpeg_scan_header {
};
/**
+ * enum v4l2_jpeg_app14_tf - APP14 transform flag
+ * According to Rec. ITU-T T.872 (06/2012) 6.5.3
+ * APP14 segment is for color encoding, it contains a transform flag,
+ * which may have values of 0, 1 and 2 and are interpreted as follows:
+ * @V4L2_JPEG_APP14_TF_CMYK_RGB: CMYK for images encoded with four components
+ * RGB for images encoded with three components
+ * @V4L2_JPEG_APP14_TF_YCBCR: an image encoded with three components using YCbCr
+ * @V4L2_JPEG_APP14_TF_YCCK: an image encoded with four components using YCCK
+ * @V4L2_JPEG_APP14_TF_UNKNOWN: indicate app14 is not present
+ */
+enum v4l2_jpeg_app14_tf {
+ V4L2_JPEG_APP14_TF_CMYK_RGB = 0,
+ V4L2_JPEG_APP14_TF_YCBCR = 1,
+ V4L2_JPEG_APP14_TF_YCCK = 2,
+ V4L2_JPEG_APP14_TF_UNKNOWN = -1,
+};
+
+/**
* struct v4l2_jpeg_header - parsed JPEG header
* @sof: pointer to frame header and size
* @sos: pointer to scan header and size
@@ -102,6 +120,7 @@ struct v4l2_jpeg_scan_header {
* order, optional
* @restart_interval: number of MCU per restart interval, Ri
* @ecs_offset: buffer offset in bytes to the entropy coded segment
+ * @app14_tf: transform flag from app14 data
*
* When this structure is passed to v4l2_jpeg_parse_header, the optional scan,
* quantization_tables, and huffman_tables pointers must be initialized to NULL
@@ -121,6 +140,7 @@ struct v4l2_jpeg_header {
struct v4l2_jpeg_reference *huffman_tables;
u16 restart_interval;
size_t ecs_offset;
+ enum v4l2_jpeg_app14_tf app14_tf;
};
int v4l2_jpeg_parse_header(void *buf, size_t len, struct v4l2_jpeg_header *out);