linux/drivers/media/platform/coda/coda-h264.c

/*
 * Coda multi-standard codec IP - H.264 helper functions
 *
 * Copyright (C) 2012 Vista Silicon S.L.
 *    Javier Martin, <javier.martin@vista-silicon.com>
 *    Xavier Duret
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/kernel.h>
#include <linux/string.h>
#include <coda.h>

static const u8 coda_filler_size[8] = { 0, 7, 14, 13, 12, 11, 10, 9 };

int coda_h264_filler_nal(int size, char *p)
{
	if (size < 6)
		return -EINVAL;

	p[0] = 0x00;
	p[1] = 0x00;
	p[2] = 0x00;
	p[3] = 0x01;
	p[4] = 0x0c;
	memset(p + 5, 0xff, size - 6);
	/* Add rbsp stop bit and trailing at the end */
	p[size - 1] = 0x80;

	return 0;
}

int coda_h264_padding(int size, char *p)
{
	int nal_size;
	int diff;

	diff = size - (size & ~0x7);
	if (diff == 0)
		return 0;

	nal_size = coda_filler_size[diff];
	coda_h264_filler_nal(nal_size, p);

	return nal_size;
}