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