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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /drivers/media/test-drivers/vidtv/vidtv_ts.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/media/test-drivers/vidtv/vidtv_ts.c')
-rw-r--r--drivers/media/test-drivers/vidtv/vidtv_ts.c136
1 files changed, 136 insertions, 0 deletions
diff --git a/drivers/media/test-drivers/vidtv/vidtv_ts.c b/drivers/media/test-drivers/vidtv/vidtv_ts.c
new file mode 100644
index 000000000..ca4bb9c40
--- /dev/null
+++ b/drivers/media/test-drivers/vidtv/vidtv_ts.c
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * The Virtual DVB test driver serves as a reference DVB driver and helps
+ * validate the existing APIs in the media subsystem. It can also aid
+ * developers working on userspace applications.
+ *
+ * Copyright (C) 2020 Daniel W. S. Almeida
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s, %d: " fmt, __func__, __LINE__
+
+#include <linux/math64.h>
+#include <linux/printk.h>
+#include <linux/ratelimit.h>
+#include <linux/types.h>
+
+#include "vidtv_common.h"
+#include "vidtv_ts.h"
+
+static u32 vidtv_ts_write_pcr_bits(u8 *to, u32 to_offset, u64 pcr)
+{
+ /* Exact same from ffmpeg. PCR is a counter driven by a 27Mhz clock */
+ u64 div;
+ u64 rem;
+ u8 *buf = to + to_offset;
+ u64 pcr_low;
+ u64 pcr_high;
+
+ div = div64_u64_rem(pcr, 300, &rem);
+
+ pcr_low = rem; /* pcr_low = pcr % 300 */
+ pcr_high = div; /* pcr_high = pcr / 300 */
+
+ *buf++ = pcr_high >> 25;
+ *buf++ = pcr_high >> 17;
+ *buf++ = pcr_high >> 9;
+ *buf++ = pcr_high >> 1;
+ *buf++ = pcr_high << 7 | pcr_low >> 8 | 0x7e;
+ *buf++ = pcr_low;
+
+ return 6;
+}
+
+void vidtv_ts_inc_cc(u8 *continuity_counter)
+{
+ ++*continuity_counter;
+ if (*continuity_counter > TS_CC_MAX_VAL)
+ *continuity_counter = 0;
+}
+
+u32 vidtv_ts_null_write_into(struct null_packet_write_args args)
+{
+ u32 nbytes = 0;
+ struct vidtv_mpeg_ts ts_header = {};
+
+ ts_header.sync_byte = TS_SYNC_BYTE;
+ ts_header.bitfield = cpu_to_be16(TS_NULL_PACKET_PID);
+ ts_header.payload = 1;
+ ts_header.continuity_counter = *args.continuity_counter;
+
+ /* copy TS header */
+ nbytes += vidtv_memcpy(args.dest_buf,
+ args.dest_offset + nbytes,
+ args.buf_sz,
+ &ts_header,
+ sizeof(ts_header));
+
+ vidtv_ts_inc_cc(args.continuity_counter);
+
+ /* fill the rest with empty data */
+ nbytes += vidtv_memset(args.dest_buf,
+ args.dest_offset + nbytes,
+ args.buf_sz,
+ TS_FILL_BYTE,
+ TS_PACKET_LEN - nbytes);
+
+ /* we should have written exactly _one_ 188byte packet */
+ if (nbytes != TS_PACKET_LEN)
+ pr_warn_ratelimited("Expected exactly %d bytes, got %d\n",
+ TS_PACKET_LEN,
+ nbytes);
+
+ return nbytes;
+}
+
+u32 vidtv_ts_pcr_write_into(struct pcr_write_args args)
+{
+ u32 nbytes = 0;
+ struct vidtv_mpeg_ts ts_header = {};
+ struct vidtv_mpeg_ts_adaption ts_adap = {};
+
+ ts_header.sync_byte = TS_SYNC_BYTE;
+ ts_header.bitfield = cpu_to_be16(args.pid);
+ ts_header.scrambling = 0;
+ /* cc is not incremented, but it is needed. see 13818-1 clause 2.4.3.3 */
+ ts_header.continuity_counter = *args.continuity_counter;
+ ts_header.payload = 0;
+ ts_header.adaptation_field = 1;
+
+ /* 13818-1 clause 2.4.3.5 */
+ ts_adap.length = 183;
+ ts_adap.PCR = 1;
+
+ /* copy TS header */
+ nbytes += vidtv_memcpy(args.dest_buf,
+ args.dest_offset + nbytes,
+ args.buf_sz,
+ &ts_header,
+ sizeof(ts_header));
+
+ /* write the adap after the TS header */
+ nbytes += vidtv_memcpy(args.dest_buf,
+ args.dest_offset + nbytes,
+ args.buf_sz,
+ &ts_adap,
+ sizeof(ts_adap));
+
+ /* write the PCR optional */
+ nbytes += vidtv_ts_write_pcr_bits(args.dest_buf,
+ args.dest_offset + nbytes,
+ args.pcr);
+
+ nbytes += vidtv_memset(args.dest_buf,
+ args.dest_offset + nbytes,
+ args.buf_sz,
+ TS_FILL_BYTE,
+ TS_PACKET_LEN - nbytes);
+
+ /* we should have written exactly _one_ 188byte packet */
+ if (nbytes != TS_PACKET_LEN)
+ pr_warn_ratelimited("Expected exactly %d bytes, got %d\n",
+ TS_PACKET_LEN,
+ nbytes);
+
+ return nbytes;
+}