diff options
| -rw-r--r-- | drivers/media/v4l2-core/v4l2-jpeg.c | 42 | ||||
| -rw-r--r-- | include/media/v4l2-jpeg.h | 20 |
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); |