1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Coda multi-standard codec IP - MPEG-2 helper functions
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright (C) 2019 Pengutronix, Philipp Zabel
6*4882a593Smuzhiyun */
7*4882a593Smuzhiyun
8*4882a593Smuzhiyun #include <linux/kernel.h>
9*4882a593Smuzhiyun #include <linux/videodev2.h>
10*4882a593Smuzhiyun #include "coda.h"
11*4882a593Smuzhiyun
coda_mpeg2_profile(int profile_idc)12*4882a593Smuzhiyun int coda_mpeg2_profile(int profile_idc)
13*4882a593Smuzhiyun {
14*4882a593Smuzhiyun switch (profile_idc) {
15*4882a593Smuzhiyun case 5:
16*4882a593Smuzhiyun return V4L2_MPEG_VIDEO_MPEG2_PROFILE_SIMPLE;
17*4882a593Smuzhiyun case 4:
18*4882a593Smuzhiyun return V4L2_MPEG_VIDEO_MPEG2_PROFILE_MAIN;
19*4882a593Smuzhiyun case 3:
20*4882a593Smuzhiyun return V4L2_MPEG_VIDEO_MPEG2_PROFILE_SNR_SCALABLE;
21*4882a593Smuzhiyun case 2:
22*4882a593Smuzhiyun return V4L2_MPEG_VIDEO_MPEG2_PROFILE_SPATIALLY_SCALABLE;
23*4882a593Smuzhiyun case 1:
24*4882a593Smuzhiyun return V4L2_MPEG_VIDEO_MPEG2_PROFILE_HIGH;
25*4882a593Smuzhiyun default:
26*4882a593Smuzhiyun return -EINVAL;
27*4882a593Smuzhiyun }
28*4882a593Smuzhiyun }
29*4882a593Smuzhiyun
coda_mpeg2_level(int level_idc)30*4882a593Smuzhiyun int coda_mpeg2_level(int level_idc)
31*4882a593Smuzhiyun {
32*4882a593Smuzhiyun switch (level_idc) {
33*4882a593Smuzhiyun case 10:
34*4882a593Smuzhiyun return V4L2_MPEG_VIDEO_MPEG2_LEVEL_LOW;
35*4882a593Smuzhiyun case 8:
36*4882a593Smuzhiyun return V4L2_MPEG_VIDEO_MPEG2_LEVEL_MAIN;
37*4882a593Smuzhiyun case 6:
38*4882a593Smuzhiyun return V4L2_MPEG_VIDEO_MPEG2_LEVEL_HIGH_1440;
39*4882a593Smuzhiyun case 4:
40*4882a593Smuzhiyun return V4L2_MPEG_VIDEO_MPEG2_LEVEL_HIGH;
41*4882a593Smuzhiyun default:
42*4882a593Smuzhiyun return -EINVAL;
43*4882a593Smuzhiyun }
44*4882a593Smuzhiyun }
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun /*
47*4882a593Smuzhiyun * Check if the buffer starts with the MPEG-2 sequence header (with or without
48*4882a593Smuzhiyun * quantization matrix) and extension header, for example:
49*4882a593Smuzhiyun *
50*4882a593Smuzhiyun * 00 00 01 b3 2d 01 e0 34 08 8b a3 81
51*4882a593Smuzhiyun * 10 11 11 12 12 12 13 13 13 13 14 14 14 14 14 15
52*4882a593Smuzhiyun * 15 15 15 15 15 16 16 16 16 16 16 16 17 17 17 17
53*4882a593Smuzhiyun * 17 17 17 17 18 18 18 19 18 18 18 19 1a 1a 1a 1a
54*4882a593Smuzhiyun * 19 1b 1b 1b 1b 1b 1c 1c 1c 1c 1e 1e 1e 1f 1f 21
55*4882a593Smuzhiyun * 00 00 01 b5 14 8a 00 01 00 00
56*4882a593Smuzhiyun *
57*4882a593Smuzhiyun * or:
58*4882a593Smuzhiyun *
59*4882a593Smuzhiyun * 00 00 01 b3 08 00 40 15 ff ff e0 28
60*4882a593Smuzhiyun * 00 00 01 b5 14 8a 00 01 00 00
61*4882a593Smuzhiyun *
62*4882a593Smuzhiyun * Returns the detected header size in bytes or 0.
63*4882a593Smuzhiyun */
coda_mpeg2_parse_headers(struct coda_ctx * ctx,u8 * buf,u32 size)64*4882a593Smuzhiyun u32 coda_mpeg2_parse_headers(struct coda_ctx *ctx, u8 *buf, u32 size)
65*4882a593Smuzhiyun {
66*4882a593Smuzhiyun static const u8 sequence_header_start[4] = { 0x00, 0x00, 0x01, 0xb3 };
67*4882a593Smuzhiyun static const union {
68*4882a593Smuzhiyun u8 extension_start[4];
69*4882a593Smuzhiyun u8 start_code_prefix[3];
70*4882a593Smuzhiyun } u = { { 0x00, 0x00, 0x01, 0xb5 } };
71*4882a593Smuzhiyun
72*4882a593Smuzhiyun if (size < 22 ||
73*4882a593Smuzhiyun memcmp(buf, sequence_header_start, 4) != 0)
74*4882a593Smuzhiyun return 0;
75*4882a593Smuzhiyun
76*4882a593Smuzhiyun if ((size == 22 ||
77*4882a593Smuzhiyun (size >= 25 && memcmp(buf + 22, u.start_code_prefix, 3) == 0)) &&
78*4882a593Smuzhiyun memcmp(buf + 12, u.extension_start, 4) == 0)
79*4882a593Smuzhiyun return 22;
80*4882a593Smuzhiyun
81*4882a593Smuzhiyun if ((size == 86 ||
82*4882a593Smuzhiyun (size > 89 && memcmp(buf + 86, u.start_code_prefix, 3) == 0)) &&
83*4882a593Smuzhiyun memcmp(buf + 76, u.extension_start, 4) == 0)
84*4882a593Smuzhiyun return 86;
85*4882a593Smuzhiyun
86*4882a593Smuzhiyun return 0;
87*4882a593Smuzhiyun }
88