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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Coda multi-standard codec IP - MPEG-4 helper functions4 *5 * Copyright (C) 2019 Pengutronix, Philipp Zabel6 */7 8#include <linux/kernel.h>9#include <linux/videodev2.h>10 11#include "coda.h"12 13int 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 31int 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 visual53 * object headers, for example:54 *55 * 00 00 01 b0 f156 * 00 00 01 b5 a9 13 00 00 01 00 00 00 01 20 0857 * d4 8d 88 00 f5 04 04 08 14 30 3f58 *59 * Returns the detected header size in bytes or 0.60 */61u32 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