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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Coda multi-standard codec IP - MPEG-2 helper functions
*
* Copyright (C) 2019 Pengutronix, Philipp Zabel
*/
#include <linux/kernel.h>
#include <linux/videodev2.h>
#include "coda.h"
int coda_mpeg2_profile(int profile_idc)
{
switch (profile_idc) {
case 5:
return V4L2_MPEG_VIDEO_MPEG2_PROFILE_SIMPLE;
case 4:
return V4L2_MPEG_VIDEO_MPEG2_PROFILE_MAIN;
case 3:
return V4L2_MPEG_VIDEO_MPEG2_PROFILE_SNR_SCALABLE;
case 2:
return V4L2_MPEG_VIDEO_MPEG2_PROFILE_SPATIALLY_SCALABLE;
case 1:
return V4L2_MPEG_VIDEO_MPEG2_PROFILE_HIGH;
default:
return -EINVAL;
}
}
int coda_mpeg2_level(int level_idc)
{
switch (level_idc) {
case 10:
return V4L2_MPEG_VIDEO_MPEG2_LEVEL_LOW;
case 8:
return V4L2_MPEG_VIDEO_MPEG2_LEVEL_MAIN;
case 6:
return V4L2_MPEG_VIDEO_MPEG2_LEVEL_HIGH_1440;
case 4:
return V4L2_MPEG_VIDEO_MPEG2_LEVEL_HIGH;
default:
return -EINVAL;
}
}
/*
* Check if the buffer starts with the MPEG-2 sequence header (with or without
* quantization matrix) and extension header, for example:
*
* 00 00 01 b3 2d 01 e0 34 08 8b a3 81
* 10 11 11 12 12 12 13 13 13 13 14 14 14 14 14 15
* 15 15 15 15 15 16 16 16 16 16 16 16 17 17 17 17
* 17 17 17 17 18 18 18 19 18 18 18 19 1a 1a 1a 1a
* 19 1b 1b 1b 1b 1b 1c 1c 1c 1c 1e 1e 1e 1f 1f 21
* 00 00 01 b5 14 8a 00 01 00 00
*
* or:
*
* 00 00 01 b3 08 00 40 15 ff ff e0 28
* 00 00 01 b5 14 8a 00 01 00 00
*
* Returns the detected header size in bytes or 0.
*/
u32 coda_mpeg2_parse_headers(struct coda_ctx *ctx, u8 *buf, u32 size)
{
static const u8 sequence_header_start[4] = { 0x00, 0x00, 0x01, 0xb3 };
static const union {
u8 extension_start[4];
u8 start_code_prefix[3];
} u = { { 0x00, 0x00, 0x01, 0xb5 } };
if (size < 22 ||
memcmp(buf, sequence_header_start, 4) != 0)
return 0;
if ((size == 22 ||
(size >= 25 && memcmp(buf + 22, u.start_code_prefix, 3) == 0)) &&
memcmp(buf + 12, u.extension_start, 4) == 0)
return 22;
if ((size == 86 ||
(size > 89 && memcmp(buf + 86, u.start_code_prefix, 3) == 0)) &&
memcmp(buf + 76, u.extension_start, 4) == 0)
return 86;
return 0;
}
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