avformat: split off generic NAL function helpers into their own file

Signed-off-by: James Almer <jamrial@gmail.com>

1 files changed, 67 insertions, 0 deletions

diff --git a/libavformat/nal.h b/libavformat/nal.h
new file mode 100644
index 0000000000..587276da84
--- /dev/null
+++ b/libavformat/nal.h
@@ -0,0 +1,67 @@
+/*
+ * NAL helper functions for muxers
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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.
+ *
+ * FFmpeg 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 FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVFORMAT_NAL_H
+#define AVFORMAT_NAL_H
+
+#include <stdint.h>
+#include "avio.h"
+
+typedef struct NALU {
+    int offset;
+    uint32_t size;
+} NALU;
+
+typedef struct NALUList {
+    NALU *nalus;
+    unsigned nalus_array_size;
+    unsigned nb_nalus;          ///< valid entries in nalus
+} NALUList;
+
+/* This function will parse the given annex B buffer and create
+ * a NALUList from it. This list can be passed to ff_nal_units_write_list()
+ * to write the access unit reformatted to mp4.
+ *
+ * @param list A NALUList. The list->nalus and list->nalus_array_size
+ *             must be valid when calling this function and may be updated.
+ *             nb_nalus is set by this function on success.
+ * @param buf  buffer containing annex B H.264 or H.265. Must be padded.
+ * @param size size of buf, excluding padding.
+ * @return < 0 on error, the size of the mp4-style packet on success.
+ */
+int ff_nal_units_create_list(NALUList *list, const uint8_t *buf, int size);
+
+/* Writes a NALUList to the specified AVIOContext. The list must originate
+ * from ff_nal_units_create_list() with the same buf. */
+void ff_nal_units_write_list(const NALUList *list, AVIOContext *pb,
+                             const uint8_t *buf);
+
+const uint8_t *ff_nal_find_startcode(const uint8_t *p, const uint8_t *end);
+const uint8_t *ff_nal_mp4_find_startcode(const uint8_t *start,
+                                         const uint8_t *end,
+                                         int nal_length_size);
+
+int ff_nal_parse_units(AVIOContext *s, const uint8_t *buf, int size);
+int ff_nal_parse_units_buf(const uint8_t *buf_in, uint8_t **buf, int *size);
+
+uint8_t *ff_nal_unit_extract_rbsp(const uint8_t *src, uint32_t src_len,
+                                  uint32_t *dst_len, int header_len);
+
+#endif /* AVFORMAT_NAL_H */