Stateless video decoding engines require both the MPEG slices and
associated metadata from the video stream in order to decode frames.

This introduces definitions for a new pixel format, describing buffers
with MPEG2 slice data, as well as a control structure for passing the
frame metadata to drivers.

This is based on work from both Florent Revest and Hugues Fruchet.

Signed-off-by: Paul Kocialkowski <paul.kocialkow...@bootlin.com>
---
 .../media/uapi/v4l/extended-controls.rst      | 122 ++++++++++++++++++
 .../media/uapi/v4l/pixfmt-compressed.rst      |   5 +
 drivers/media/v4l2-core/v4l2-ctrls.c          |  54 ++++++++
 drivers/media/v4l2-core/v4l2-ioctl.c          |   1 +
 include/media/v4l2-ctrls.h                    |  18 ++-
 include/uapi/linux/v4l2-controls.h            |  43 ++++++
 include/uapi/linux/videodev2.h                |   5 +
 7 files changed, 241 insertions(+), 7 deletions(-)

diff --git a/Documentation/media/uapi/v4l/extended-controls.rst 
b/Documentation/media/uapi/v4l/extended-controls.rst
index 9f7312bf3365..4a29d89fd9ac 100644
--- a/Documentation/media/uapi/v4l/extended-controls.rst
+++ b/Documentation/media/uapi/v4l/extended-controls.rst
@@ -1497,6 +1497,128 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type -
 
 
 
+.. _v4l2-mpeg-mpeg2:
+
+``V4L2_CID_MPEG_VIDEO_MPEG2_SLICE_PARAMS (struct)``
+    Specifies the slice parameters (also known as slice header) for the
+    associated MPEG-2 slice data. This includes all the necessary
+    parameters for configuring a hardware decoder pipeline for MPEG-2.
+
+.. tabularcolumns:: |p{2.0cm}|p{4.0cm}|p{11.0cm}|
+
+.. c:type:: v4l2_ctrl_mpeg2_slice_params
+
+.. cssclass:: longtable
+
+.. flat-table:: struct v4l2_ctrl_mpeg2_slice_params
+    :header-rows:  0
+    :stub-columns: 0
+    :widths:       1 1 2
+
+    * - __u32
+      - ``slice_len``
+      - Length (in bits) of the current slice data.
+    * - __u32
+      - ``slice_pos``
+      - Position (in bits) of the current slice data, relative to the
+        frame start.
+    * - __u16
+      - ``width``
+      - Width of the corresponding output frame for the current slice.
+    * - __u16
+      - ``height``
+      - Height of the corresponding output frame for the current slice.
+    * - __u8
+      - ``slice_type``
+      - Picture coding type for the frame covered by the current slice
+        (V4L2_MPEG2_SLICE_TYPE_I, V4L2_MPEG2_SLICE_TYPE_P or
+        V4L2_MPEG2_SLICE_PCT_B).
+    * - __u8
+      - ``f_code[2][2]``
+      - Motion vector codes.
+    * - __u8
+      - ``intra_dc_precision``
+      - Precision of Discrete Cosine transform (0: 8 bits precision,
+        1: 9 bits precision, 2: 10 bits precision, 11: 11 bits precision).
+    * - __u8
+      - ``picture_structure``
+      - Picture structure (1: interlaced top field,
+        2: interlaced bottom field, 3: progressive frame).
+    * - __u8
+      - ``top_field_first``
+      - If set to 1 and interlaced stream, top field is output first.
+    * - __u8
+      - ``frame_pred_frame_dct``
+      - If set to 1, only frame-DCT and frame prediction are used.
+    * - __u8
+      - ``concealment_motion_vectors``
+      -  If set to 1, motion vectors are coded for intra macroblocks.
+    * - __u8
+      - ``q_scale_type``
+      - This flag affects the inverse quantisation process.
+    * - __u8
+      - ``intra_vlc_format``
+      - This flag affects the decoding of transform coefficient data.
+    * - __u8
+      - ``alternate_scan``
+      - This flag affects the decoding of transform coefficient data.
+    * - __u8
+      - ``backward_ref_index``
+      - Index for the V4L2 buffer to use as backward reference, used with
+        B-coded and P-coded frames.
+    * - __u8
+      - ``forward_ref_index``
+      - Index for the V4L2 buffer to use as forward reference, used with
+        P-coded frames.
+    * - :cspan:`2`
+
+``V4L2_CID_MPEG_VIDEO_MPEG2_QUANTIZATION (struct)``
+    Specifies quantization matrices for the associated MPEG-2 slice data.
+
+.. tabularcolumns:: |p{2.0cm}|p{4.0cm}|p{11.0cm}|
+
+.. c:type:: v4l2_ctrl_mpeg2_quantization
+
+.. cssclass:: longtable
+
+.. flat-table:: struct v4l2_ctrl_mpeg2_quantization
+    :header-rows:  0
+    :stub-columns: 0
+    :widths:       1 1 2
+
+    * - __u8
+      - ``load_intra_quantiser_matrix``
+      - One bit to indicate whether to load the intra quantiser matrix.
+    * - __u32
+      - ``load_non_intra_quantiser_matrix``
+      - One bit to indicate whether to load the non-intra quantiser matrix.
+    * - __u32
+      - ``load_chroma_intra_quantiser_matrix``
+      - One bit to indicate whether to load the chroma intra quantiser matrix,
+        only relevant for non-4:2:0 YUV formats.
+    * - __u32
+      - ``load_chroma_non_intra_quantiser_matrix``
+      - One bit to indicate whether to load the non-chroma intra quantiser
+        matrix, only relevant for non-4:2:0 YUV formats.
+    * - __u32
+      - ``intra_quantiser_matrix[64]``
+      - The intra quantiser matrix coefficients, in zigzag scanning order.
+        It is relevant for both luma and chroma components, although it can be
+        superseded by the chroma-specific matrix for non-4:2:0 YUV formats.
+    * - __u32
+      - ``non_intra_quantiser_matrix[64]``
+      - The non-intra quantiser matrix coefficients, in zigzag scanning order.
+        It is relevant for both luma and chroma components, although it can be
+        superseded by the chroma-specific matrix for non-4:2:0 YUV formats.
+    * - __u32
+      - ``chroma_intra_quantiser_matrix[64]``
+      - The intra quantiser matrix coefficients for the chroma YUV component,
+        in zigzag scanning order. Only relevant for non-4:2:0 YUV formats.
+    * - __u32
+      - ``chroma_non_intra_quantiser_matrix[64]``
+      - The non-intra quantiser matrix coefficients for the chroma YUV 
component,
+        in zigzag scanning order. Only relevant for non-4:2:0 YUV formats.
+    * - :cspan:`2`
 
 MFC 5.1 MPEG Controls
 ---------------------
diff --git a/Documentation/media/uapi/v4l/pixfmt-compressed.rst 
b/Documentation/media/uapi/v4l/pixfmt-compressed.rst
index abec03937bb3..4e73f62b5163 100644
--- a/Documentation/media/uapi/v4l/pixfmt-compressed.rst
+++ b/Documentation/media/uapi/v4l/pixfmt-compressed.rst
@@ -60,6 +60,11 @@ Compressed Formats
       - ``V4L2_PIX_FMT_MPEG2``
       - 'MPG2'
       - MPEG2 video elementary stream.
+    * .. _V4L2-PIX-FMT-MPEG2-SLICE:
+
+      - ``V4L2_PIX_FMT_MPEG2_SLICE``
+      - 'MG2S'
+      - MPEG2 parsed slice data, as extracted from the MPEG2 bitstream.
     * .. _V4L2-PIX-FMT-MPEG4:
 
       - ``V4L2_PIX_FMT_MPEG4``
diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c 
b/drivers/media/v4l2-core/v4l2-ctrls.c
index 3610dce3a4f8..22483d894259 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -844,6 +844,8 @@ const char *v4l2_ctrl_get_name(u32 id)
        case V4L2_CID_MPEG_VIDEO_MV_V_SEARCH_RANGE:             return 
"Vertical MV Search Range";
        case V4L2_CID_MPEG_VIDEO_REPEAT_SEQ_HEADER:             return "Repeat 
Sequence Header";
        case V4L2_CID_MPEG_VIDEO_FORCE_KEY_FRAME:               return "Force 
Key Frame";
+       case V4L2_CID_MPEG_VIDEO_MPEG2_SLICE_PARAMS:            return "MPEG2 
Slice Header";
+       case V4L2_CID_MPEG_VIDEO_MPEG2_QUANTIZATION:            return "MPEG2 
Quantization Matrices";
 
        /* VPX controls */
        case V4L2_CID_MPEG_VIDEO_VPX_NUM_PARTITIONS:            return "VPX 
Number of Partitions";
@@ -1292,6 +1294,12 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum 
v4l2_ctrl_type *type,
        case V4L2_CID_RDS_TX_ALT_FREQS:
                *type = V4L2_CTRL_TYPE_U32;
                break;
+       case V4L2_CID_MPEG_VIDEO_MPEG2_SLICE_PARAMS:
+               *type = V4L2_CTRL_TYPE_MPEG2_SLICE_PARAMS;
+               break;
+       case V4L2_CID_MPEG_VIDEO_MPEG2_QUANTIZATION:
+               *type = V4L2_CTRL_TYPE_MPEG2_QUANTIZATION;
+               break;
        default:
                *type = V4L2_CTRL_TYPE_INTEGER;
                break;
@@ -1550,6 +1558,7 @@ static void std_log(const struct v4l2_ctrl *ctrl)
 static int std_validate(const struct v4l2_ctrl *ctrl, u32 idx,
                        union v4l2_ctrl_ptr ptr)
 {
+       struct v4l2_ctrl_mpeg2_slice_params *p_mpeg2_slice_params;
        size_t len;
        u64 offset;
        s64 val;
@@ -1612,6 +1621,45 @@ static int std_validate(const struct v4l2_ctrl *ctrl, 
u32 idx,
                        return -ERANGE;
                return 0;
 
+       case V4L2_CTRL_TYPE_MPEG2_SLICE_PARAMS:
+               p_mpeg2_slice_params = ptr.p;
+
+               switch (p_mpeg2_slice_params->intra_dc_precision) {
+               case 0: /* 8 bits */
+               case 1: /* 9 bits */
+               case 11: /* 11 bits */
+                       break;
+               default:
+                       return -EINVAL;
+               }
+
+               switch (p_mpeg2_slice_params->picture_structure) {
+               case 1: /* interlaced top field */
+               case 2: /* interlaced bottom field */
+               case 3: /* progressive */
+                       break;
+               default:
+                       return -EINVAL;
+               }
+
+               switch (p_mpeg2_slice_params->slice_type) {
+               case V4L2_MPEG2_SLICE_TYPE_I:
+               case V4L2_MPEG2_SLICE_TYPE_P:
+               case V4L2_MPEG2_SLICE_TYPE_B:
+                       break;
+               default:
+                       return -EINVAL;
+               }
+
+               if (p_mpeg2_slice_params->backward_ref_index > VIDEO_MAX_FRAME 
||
+                   p_mpeg2_slice_params->forward_ref_index > VIDEO_MAX_FRAME)
+                       return -EINVAL;
+
+               return 0;
+
+       case V4L2_CTRL_TYPE_MPEG2_QUANTIZATION:
+               return 0;
+
        default:
                return -EINVAL;
        }
@@ -2186,6 +2234,12 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct 
v4l2_ctrl_handler *hdl,
        case V4L2_CTRL_TYPE_U32:
                elem_size = sizeof(u32);
                break;
+       case V4L2_CTRL_TYPE_MPEG2_SLICE_PARAMS:
+               elem_size = sizeof(struct v4l2_ctrl_mpeg2_slice_params);
+               break;
+       case V4L2_CTRL_TYPE_MPEG2_QUANTIZATION:
+               elem_size = sizeof(struct v4l2_ctrl_mpeg2_quantization);
+               break;
        default:
                if (type < V4L2_CTRL_COMPOUND_TYPES)
                        elem_size = sizeof(s32);
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c 
b/drivers/media/v4l2-core/v4l2-ioctl.c
index 44fc0102221f..68e914b83a03 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -1304,6 +1304,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
                case V4L2_PIX_FMT_H263:         descr = "H.263"; break;
                case V4L2_PIX_FMT_MPEG1:        descr = "MPEG-1 ES"; break;
                case V4L2_PIX_FMT_MPEG2:        descr = "MPEG-2 ES"; break;
+               case V4L2_PIX_FMT_MPEG2_SLICE:  descr = "MPEG-2 parsed slice 
data"; break;
                case V4L2_PIX_FMT_MPEG4:        descr = "MPEG-4 part 2 ES"; 
break;
                case V4L2_PIX_FMT_XVID:         descr = "Xvid"; break;
                case V4L2_PIX_FMT_VC1_ANNEX_G:  descr = "VC-1 (SMPTE 412M Annex 
G)"; break;
diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
index 34ee3167d7dd..83eff6f91ed2 100644
--- a/include/media/v4l2-ctrls.h
+++ b/include/media/v4l2-ctrls.h
@@ -35,13 +35,15 @@ struct poll_table_struct;
 
 /**
  * union v4l2_ctrl_ptr - A pointer to a control value.
- * @p_s32:     Pointer to a 32-bit signed value.
- * @p_s64:     Pointer to a 64-bit signed value.
- * @p_u8:      Pointer to a 8-bit unsigned value.
- * @p_u16:     Pointer to a 16-bit unsigned value.
- * @p_u32:     Pointer to a 32-bit unsigned value.
- * @p_char:    Pointer to a string.
- * @p:         Pointer to a compound value.
+ * @p_s32:                     Pointer to a 32-bit signed value.
+ * @p_s64:                     Pointer to a 64-bit signed value.
+ * @p_u8:                      Pointer to a 8-bit unsigned value.
+ * @p_u16:                     Pointer to a 16-bit unsigned value.
+ * @p_u32:                     Pointer to a 32-bit unsigned value.
+ * @p_char:                    Pointer to a string.
+ * @p_mpeg2_slice_params:      Pointer to a MPEG2 slice parameters structure.
+ * @p_mpeg2_quantization:      Pointer to a MPEG2 quantization data structure.
+ * @p:                         Pointer to a compound value.
  */
 union v4l2_ctrl_ptr {
        s32 *p_s32;
@@ -50,6 +52,8 @@ union v4l2_ctrl_ptr {
        u16 *p_u16;
        u32 *p_u32;
        char *p_char;
+       struct v4l2_ctrl_mpeg2_slice_params *p_mpeg2_slice_params;
+       struct v4l2_ctrl_mpeg2_quantization *p_mpeg2_quantization;
        void *p;
 };
 
diff --git a/include/uapi/linux/v4l2-controls.h 
b/include/uapi/linux/v4l2-controls.h
index e4ee10ee917d..ce6de781037a 100644
--- a/include/uapi/linux/v4l2-controls.h
+++ b/include/uapi/linux/v4l2-controls.h
@@ -557,6 +557,9 @@ enum v4l2_mpeg_video_mpeg4_profile {
 };
 #define V4L2_CID_MPEG_VIDEO_MPEG4_QPEL         (V4L2_CID_MPEG_BASE+407)
 
+#define V4L2_CID_MPEG_VIDEO_MPEG2_SLICE_PARAMS (V4L2_CID_MPEG_BASE+450)
+#define V4L2_CID_MPEG_VIDEO_MPEG2_QUANTIZATION (V4L2_CID_MPEG_BASE+451)
+
 /*  Control IDs for VP8 streams
  *  Although VP8 is not part of MPEG we add these controls to the MPEG class
  *  as that class is already handling other video compression standards
@@ -1092,4 +1095,44 @@ enum v4l2_detect_md_mode {
 #define V4L2_CID_DETECT_MD_THRESHOLD_GRID      (V4L2_CID_DETECT_CLASS_BASE + 3)
 #define V4L2_CID_DETECT_MD_REGION_GRID         (V4L2_CID_DETECT_CLASS_BASE + 4)
 
+#define V4L2_MPEG2_SLICE_TYPE_I                        1
+#define V4L2_MPEG2_SLICE_TYPE_P                        2
+#define V4L2_MPEG2_SLICE_TYPE_B                        3
+#define V4L2_MPEG2_SLICE_TYPE_D                        4
+
+struct v4l2_ctrl_mpeg2_slice_params {
+       __u32   slice_len;
+       __u32   slice_pos;
+
+       __u16   width;
+       __u16   height;
+
+       __u8    slice_type;
+       __u8    f_code[2][2];
+
+       __u8    intra_dc_precision;
+       __u8    picture_structure;
+       __u8    top_field_first;
+       __u8    frame_pred_frame_dct;
+       __u8    concealment_motion_vectors;
+       __u8    q_scale_type;
+       __u8    intra_vlc_format;
+       __u8    alternate_scan;
+
+       __u8    backward_ref_index;
+       __u8    forward_ref_index;
+};
+
+struct v4l2_ctrl_mpeg2_quantization {
+       __u8    load_intra_quantiser_matrix : 1;
+       __u8    load_non_intra_quantiser_matrix : 1;
+       __u8    load_chroma_intra_quantiser_matrix : 1;
+       __u8    load_chroma_non_intra_quantiser_matrix : 1;
+
+       __u8    intra_quantiser_matrix[64];
+       __u8    non_intra_quantiser_matrix[64];
+       __u8    chroma_intra_quantiser_matrix[64];
+       __u8    chroma_non_intra_quantiser_matrix[64];
+};
+
 #endif
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 1f6c4b52baae..d171361ed9b3 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -629,6 +629,7 @@ struct v4l2_pix_format {
 #define V4L2_PIX_FMT_H263     v4l2_fourcc('H', '2', '6', '3') /* H263          
*/
 #define V4L2_PIX_FMT_MPEG1    v4l2_fourcc('M', 'P', 'G', '1') /* MPEG-1 ES     
*/
 #define V4L2_PIX_FMT_MPEG2    v4l2_fourcc('M', 'P', 'G', '2') /* MPEG-2 ES     
*/
+#define V4L2_PIX_FMT_MPEG2_SLICE v4l2_fourcc('M', 'G', '2', 'S') /* MPEG-2 
parsed slice data */
 #define V4L2_PIX_FMT_MPEG4    v4l2_fourcc('M', 'P', 'G', '4') /* MPEG-4 part 2 
ES */
 #define V4L2_PIX_FMT_XVID     v4l2_fourcc('X', 'V', 'I', 'D') /* Xvid          
 */
 #define V4L2_PIX_FMT_VC1_ANNEX_G v4l2_fourcc('V', 'C', '1', 'G') /* SMPTE 421M 
Annex G compliant stream */
@@ -1587,6 +1588,8 @@ struct v4l2_ext_control {
                __u8 __user *p_u8;
                __u16 __user *p_u16;
                __u32 __user *p_u32;
+               struct v4l2_ctrl_mpeg2_slice_params __user 
*p_mpeg2_slice_params;
+               struct v4l2_ctrl_mpeg2_quantization __user 
*p_mpeg2_quantization;
                void __user *ptr;
        };
 } __attribute__ ((packed));
@@ -1632,6 +1635,8 @@ enum v4l2_ctrl_type {
        V4L2_CTRL_TYPE_U8            = 0x0100,
        V4L2_CTRL_TYPE_U16           = 0x0101,
        V4L2_CTRL_TYPE_U32           = 0x0102,
+       V4L2_CTRL_TYPE_MPEG2_SLICE_PARAMS = 0x0103,
+       V4L2_CTRL_TYPE_MPEG2_QUANTIZATION = 0x0104,
 };
 
 /*  Used in the VIDIOC_QUERYCTRL ioctl for querying controls */
-- 
2.18.0

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