libhb: add generic code for converting NAL

unit bitstreams (H.264, HEVC) to and from
Annex B format.

Only used by QSV for now, but could
always come in handy down the road.

May also fix an issue introduced
by the recent QSV cleanup patchset.


git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@6156 b64f7644-9d1e-0410-96f1-a4d463321fa5

1 files changed, 51 insertions, 0 deletions

diff --git a/libhb/nal_units.h b/libhb/nal_units.h
new file mode 100644
index 000000000..734362de9
--- /dev/null
+++ b/libhb/nal_units.h
@@ -0,0 +1,51 @@
+/* nal_units.h
+ *
+ * Copyright (c) 2003-2014 HandBrake Team
+ * This file is part of the HandBrake source code.
+ * Homepage: <http://handbrake.fr/>.
+ * It may be used under the terms of the GNU General Public License v2.
+ * For full terms see the file COPYING file or visit http://www.gnu.org/licenses/gpl-2.0.html
+ */
+
+#ifndef HB_NAL_UNITS_H
+#define HB_NAL_UNITS_H
+
+#include <stdint.h>
+
+#include "common.h"
+
+/*
+ * Write a NAL unit of the specified size to the provided
+ * output buffer, using the requested output format.
+ * Returns the amount (in bytes) of data written to the buffer.
+ *
+ * The provided NAL unit must start with the NAL unit header.
+ *
+ * Note: the buffer is assumed to be large enough to hold the NAL unit
+ * as well as any additonal data the function may prepend/append to it.
+ *
+ * The caller may check the minimum required buffer size by passing a
+ * NULL buffer to the fucntion and checking the returned size value.
+ */
+size_t hb_nal_unit_write_annexb(uint8_t *buf, const uint8_t *nal_unit, const size_t nal_unit_size);
+size_t hb_nal_unit_write_isomp4(uint8_t *buf, const uint8_t *nal_unit, const size_t nal_unit_size);
+
+/*
+ * Search the provided data buffer for NAL units in Annex B format.
+ *
+ * Returns a pointer to the start (start code prefix excluded) of the
+ * first NAL unit found, or NULL if no NAL units were found in the buffer.
+ *
+ * On input,  size holds the length of the provided data buffer.
+ * On output, size holds the length of the returned NAL unit.
+ */
+uint8_t* hb_annexb_find_next_nalu(const uint8_t *start, size_t *size);
+
+/*
+ * Returns a newly-allocated buffer holding a copy of the provided
+ * NAL unit bitstream data, converted to the requested format.
+ */
+hb_buffer_t* hb_nal_bitstream_annexb_to_mp4(const uint8_t *data, const size_t size);
+hb_buffer_t* hb_nal_bitstream_mp4_to_annexb(const uint8_t *data, const size_t size, const uint8_t nal_length_size);
+
+#endif // HB_NAL_UNITS_H