1 files changed, 87 insertions, 0 deletions
diff --git a/drivers/media/platform/chips-media/coda-mpeg4.c b/drivers/media/platform/chips-media/coda-mpeg4.c
new file mode 100644
index 000000000000..483a4fba1b4f
--- /dev/null
+++ b/drivers/media/platform/chips-media/coda-mpeg4.c
@@ -0,0 +1,87 @@
+// 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;
+}