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 } 88