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

88 lines
2.0 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Coda multi-standard codec IP - MPEG-4 helper functions
*
* Copyright (C) 2019 Pengutronix, Philipp Zabel
*/
#include <linux/kernel.h>
#include <linux/videodev2.h>
#include "coda.h"
int coda_mpeg4_profile(int profile_idc)
{
switch (profile_idc) {
case 0:
return V4L2_MPEG_VIDEO_MPEG4_PROFILE_SIMPLE;
case 15:
return V4L2_MPEG_VIDEO_MPEG4_PROFILE_ADVANCED_SIMPLE;
case 2:
return V4L2_MPEG_VIDEO_MPEG4_PROFILE_CORE;
case 1:
return V4L2_MPEG_VIDEO_MPEG4_PROFILE_SIMPLE_SCALABLE;
case 11:
return V4L2_MPEG_VIDEO_MPEG4_PROFILE_ADVANCED_CODING_EFFICIENCY;
default:
return -EINVAL;
}
}
int coda_mpeg4_level(int level_idc)
{
switch (level_idc) {
case 0:
return V4L2_MPEG_VIDEO_MPEG4_LEVEL_0;
case 1:
return V4L2_MPEG_VIDEO_MPEG4_LEVEL_1;
case 2:
return V4L2_MPEG_VIDEO_MPEG4_LEVEL_2;
case 3:
return V4L2_MPEG_VIDEO_MPEG4_LEVEL_3;
case 4:
return V4L2_MPEG_VIDEO_MPEG4_LEVEL_4;
case 5:
return V4L2_MPEG_VIDEO_MPEG4_LEVEL_5;
default:
return -EINVAL;
}
}
/*
* Check if the buffer starts with the MPEG-4 visual object sequence and visual
* object headers, for example:
*
* 00 00 01 b0 f1
* 00 00 01 b5 a9 13 00 00 01 00 00 00 01 20 08
* d4 8d 88 00 f5 04 04 08 14 30 3f
*
* Returns the detected header size in bytes or 0.
*/
u32 coda_mpeg4_parse_headers(struct coda_ctx *ctx, u8 *buf, u32 size)
{
static const u8 vos_start[4] = { 0x00, 0x00, 0x01, 0xb0 };
static const union {
u8 vo_start[4];
u8 start_code_prefix[3];
} u = { { 0x00, 0x00, 0x01, 0xb5 } };
if (size < 30 ||
memcmp(buf, vos_start, 4) != 0 ||
memcmp(buf + 5, u.vo_start, 4) != 0)
return 0;
if (size == 30 ||
(size >= 33 && memcmp(buf + 30, u.start_code_prefix, 3) == 0))
return 30;
if (size == 31 ||
(size >= 34 && memcmp(buf + 31, u.start_code_prefix, 3) == 0))
return 31;
if (size == 32 ||
(size >= 35 && memcmp(buf + 32, u.start_code_prefix, 3) == 0))
return 32;
return 0;
}