root/drivers/media/platform/coda/coda-mpeg4.c

DEFINITIONS

1. coda_mpeg4_profile
2. coda_mpeg4_level
3. coda_mpeg4_parse_headers

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Coda multi-standard codec IP - MPEG-4 helper functions
   4  *
   5  * Copyright (C) 2019 Pengutronix, Philipp Zabel
   6  */
   7 
   8 #include <linux/kernel.h>
   9 #include <linux/videodev2.h>
  10 
  11 #include "coda.h"
  12 
  13 int coda_mpeg4_profile(int profile_idc)
  14 {
  15         switch (profile_idc) {
  16         case 0:
  17                 return V4L2_MPEG_VIDEO_MPEG4_PROFILE_SIMPLE;
  18         case 15:
  19                 return V4L2_MPEG_VIDEO_MPEG4_PROFILE_ADVANCED_SIMPLE;
  20         case 2:
  21                 return V4L2_MPEG_VIDEO_MPEG4_PROFILE_CORE;
  22         case 1:
  23                 return V4L2_MPEG_VIDEO_MPEG4_PROFILE_SIMPLE_SCALABLE;
  24         case 11:
  25                 return V4L2_MPEG_VIDEO_MPEG4_PROFILE_ADVANCED_CODING_EFFICIENCY;
  26         default:
  27                 return -EINVAL;
  28         }
  29 }
  30 
  31 int coda_mpeg4_level(int level_idc)
  32 {
  33         switch (level_idc) {
  34         case 0:
  35                 return V4L2_MPEG_VIDEO_MPEG4_LEVEL_0;
  36         case 1:
  37                 return V4L2_MPEG_VIDEO_MPEG4_LEVEL_1;
  38         case 2:
  39                 return V4L2_MPEG_VIDEO_MPEG4_LEVEL_2;
  40         case 3:
  41                 return V4L2_MPEG_VIDEO_MPEG4_LEVEL_3;
  42         case 4:
  43                 return V4L2_MPEG_VIDEO_MPEG4_LEVEL_4;
  44         case 5:
  45                 return V4L2_MPEG_VIDEO_MPEG4_LEVEL_5;
  46         default:
  47                 return -EINVAL;
  48         }
  49 }
  50 
  51 /*
  52  * Check if the buffer starts with the MPEG-4 visual object sequence and visual
  53  * object headers, for example:
  54  *
  55  *   00 00 01 b0 f1
  56  *   00 00 01 b5 a9 13 00 00 01 00 00 00 01 20 08
  57  *               d4 8d 88 00 f5 04 04 08 14 30 3f
  58  *
  59  * Returns the detected header size in bytes or 0.
  60  */
  61 u32 coda_mpeg4_parse_headers(struct coda_ctx *ctx, u8 *buf, u32 size)
  62 {
  63         static const u8 vos_start[4] = { 0x00, 0x00, 0x01, 0xb0 };
  64         static const union {
  65                 u8 vo_start[4];
  66                 u8 start_code_prefix[3];
  67         } u = { { 0x00, 0x00, 0x01, 0xb5 } };
  68 
  69         if (size < 30 ||
  70             memcmp(buf, vos_start, 4) != 0 ||
  71             memcmp(buf + 5, u.vo_start, 4) != 0)
  72                 return 0;
  73 
  74         if (size == 30 ||
  75             (size >= 33 && memcmp(buf + 30, u.start_code_prefix, 3) == 0))
  76                 return 30;
  77 
  78         if (size == 31 ||
  79             (size >= 34 && memcmp(buf + 31, u.start_code_prefix, 3) == 0))
  80                 return 31;
  81 
  82         if (size == 32 ||
  83             (size >= 35 && memcmp(buf + 32, u.start_code_prefix, 3) == 0))
  84                 return 32;
  85 
  86         return 0;
  87 }