lavc: VAAPI H.264 encoder

Signed-off-by: Anton Khirnov <anton@khirnov.net>

1 files changed, 68 insertions, 0 deletions

diff --git a/libavcodec/vaapi_encode_h26x.c b/libavcodec/vaapi_encode_h26x.c
new file mode 100644
index 0000000000..bf9eb92135
--- /dev/null
+++ b/libavcodec/vaapi_encode_h26x.c
@@ -0,0 +1,68 @@
+/*
+ * This file is part of Libav.
+ *
+ * Libav is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * Libav is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <stdint.h>
+
+#include "vaapi_encode_h26x.h"
+
+int ff_vaapi_encode_h26x_nal_unit_to_byte_stream(uint8_t *dst, size_t *dst_bit_len,
+                                                 uint8_t *src, size_t src_bit_len)
+{
+    size_t dp, sp;
+    int zero_run = 0;
+    size_t dst_len = *dst_bit_len / 8;
+    size_t src_len = (src_bit_len + 7) / 8;
+    int trailing_zeroes = src_len * 8 - src_bit_len;
+
+    if (dst_len < src_len + 4) {
+        // Definitely doesn't fit.
+        goto fail;
+    }
+
+    // Start code.
+    dst[0] = dst[1] = dst[2] = 0;
+    dst[3] = 1;
+    dp = 4;
+
+    for (sp = 0; sp < src_len; sp++) {
+        if (dp >= dst_len)
+            goto fail;
+        if (zero_run < 2) {
+            if (src[sp] == 0)
+                ++zero_run;
+            else
+                zero_run = 0;
+        } else {
+            if ((src[sp] & ~3) == 0) {
+                // emulation_prevention_three_byte
+                dst[dp++] = 3;
+                if (dp >= dst_len)
+                    goto fail;
+            }
+            zero_run = src[sp] == 0;
+        }
+        dst[dp++] = src[sp];
+    }
+
+    *dst_bit_len = 8 * dp - trailing_zeroes;
+    return 0;
+
+fail:
+    *dst_bit_len = 0;
+    return AVERROR(ENOSPC);
+}