| Message ID | 20210111192822.12178-7-mirela.rabulea@oss.nxp.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add V4L2 driver for i.MX8 JPEG Encoder/Decoder | expand |
On Mon, 2021-01-11 at 21:28 +0200, Mirela Rabulea wrote: > From: Mirela Rabulea <mirela.rabulea@nxp.com> > > 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> > --- > Changes in v7: > Check there are 6 bytes available in the stream before checking for "Adobe\0" > Change jpeg_parse_app14_data function to differentiate between the 3 scenarios: app14 missing, or app14 present but with/without parsing errors: > App14 missing => Added V4L2_JPEG_APP14_TF_UNKNOWN to the enum v4l2_jpeg_app14_tf, use it to indicate app14 & TF is missing > App14 present without parsing errors => Return the transform flag value as enum v4l2_jpeg_app14_tf (new paramater of jpeg_parse_app14_data function) > App14 present with parsing errors => Return -EINVAL from jpeg_parse_app14_data, also return from calling function (v4l2_jpeg_parse_header) when this error is met. > > drivers/media/v4l2-core/v4l2-jpeg.c | 47 +++++++++++++++++++++++++++-- > include/media/v4l2-jpeg.h | 20 ++++++++++++ > 2 files changed, 65 insertions(+), 2 deletions(-) > > diff --git a/drivers/media/v4l2-core/v4l2-jpeg.c b/drivers/media/v4l2-core/v4l2-jpeg.c > index 8947fd95c6f1..8d5fedb136dd 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 > @@ -444,8 +445,44 @@ 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 = lp - 2 - 11; > + ret = jpeg_skip(stream, skip); > + if (ret < 0) > + return ret; > + > + return 0; This could be simplified to return jpeg_skip(stream, skip); although it would be better style to move the *tf = ... assignment down past the last error return instead. Either way, Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de> regards Philipp
diff --git a/drivers/media/v4l2-core/v4l2-jpeg.c b/drivers/media/v4l2-core/v4l2-jpeg.c index 8947fd95c6f1..8d5fedb136dd 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 @@ -444,8 +445,44 @@ 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 = lp - 2 - 11; + ret = jpeg_skip(stream, skip); + if (ret < 0) + return ret; + + return 0; +} + /** - * jpeg_parse_header - locate marker segments and optionally parse headers + * v4l2_jpeg_parse_header - locate marker segments and optionally parse headers * @buf: address of the JPEG buffer, should start with a SOI marker * @len: length of the JPEG buffer * @out: returns marker segment positions and optionally parsed headers @@ -476,6 +513,9 @@ 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 +559,10 @@ 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 ddba2a56c321..bae5a68bab6a 100644 --- a/include/media/v4l2-jpeg.h +++ b/include/media/v4l2-jpeg.h @@ -87,6 +87,24 @@ struct v4l2_jpeg_scan_header { /* Ss, Se, Ah, and Al are not used by any driver */ }; +/** + * 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 @@ -100,6 +118,7 @@ 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 @@ -119,6 +138,7 @@ 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);