From 1bd2d763d4ad7e66017c51cdbcb395711e6a53e6 Mon Sep 17 00:00:00 2001
From: Aurelien Jacobs <aurel@gnuage.org>
Date: Fri, 11 Jan 2008 01:24:55 +0000
Subject: Move isom_write_avcc() and related functions into a separate file.

Originally committed as revision 11498 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
 libavformat/avc.c | 135 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 135 insertions(+)
 create mode 100644 libavformat/avc.c

(limited to 'libavformat/avc.c')

diff --git a/libavformat/avc.c b/libavformat/avc.c
new file mode 100644
index 0000000000..e9199de1fc
--- /dev/null
+++ b/libavformat/avc.c
@@ -0,0 +1,135 @@
+/*
+ * AVC helper functions for muxers
+ * Copyright (c) 2006 Baptiste Coudurier <baptiste.coudurier@smartjog.com>
+ *
+ * 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
+ */
+#include "avformat.h"
+#include "avio.h"
+
+static uint8_t *avc_find_startcode( uint8_t *p, uint8_t *end )
+{
+    uint8_t *a = p + 4 - ((long)p & 3);
+
+    for( end -= 3; p < a && p < end; p++ ) {
+        if( p[0] == 0 && p[1] == 0 && p[2] == 1 )
+            return p;
+    }
+
+    for( end -= 3; p < end; p += 4 ) {
+        uint32_t x = *(uint32_t*)p;
+//      if( (x - 0x01000100) & (~x) & 0x80008000 ) // little endian
+//      if( (x - 0x00010001) & (~x) & 0x00800080 ) // big endian
+        if( (x - 0x01010101) & (~x) & 0x80808080 ) { // generic
+            if( p[1] == 0 ) {
+                if( p[0] == 0 && p[2] == 1 )
+                    return p-1;
+                if( p[2] == 0 && p[3] == 1 )
+                    return p;
+            }
+            if( p[3] == 0 ) {
+                if( p[2] == 0 && p[4] == 1 )
+                    return p+1;
+                if( p[4] == 0 && p[5] == 1 )
+                    return p+2;
+            }
+        }
+    }
+
+    for( end += 3; p < end; p++ ) {
+        if( p[0] == 0 && p[1] == 0 && p[2] == 1 )
+            return p;
+    }
+
+    return end + 3;
+}
+
+int avc_parse_nal_units(uint8_t *buf_in, uint8_t **buf, int *size)
+{
+    ByteIOContext *pb;
+    uint8_t *p = buf_in;
+    uint8_t *end = p + *size;
+    uint8_t *nal_start, *nal_end;
+    int ret = url_open_dyn_buf(&pb);
+    if(ret < 0)
+        return ret;
+
+    nal_start = avc_find_startcode(p, end);
+    while (nal_start < end) {
+        while(!*(nal_start++));
+        nal_end = avc_find_startcode(nal_start, end);
+        put_be32(pb, nal_end - nal_start);
+        put_buffer(pb, nal_start, nal_end - nal_start);
+        nal_start = nal_end;
+    }
+    av_freep(buf);
+    *size = url_close_dyn_buf(pb, buf);
+    return 0;
+}
+
+int isom_write_avcc(ByteIOContext *pb, uint8_t *data, int len)
+{
+    if (len > 6) {
+        /* check for h264 start code */
+        if (AV_RB32(data) == 0x00000001) {
+            uint8_t *buf=NULL, *end;
+            uint32_t sps_size=0, pps_size=0;
+            uint8_t *sps=0, *pps=0;
+
+            int ret = avc_parse_nal_units(data, &buf, &len);
+            if (ret < 0)
+                return ret;
+            data = buf;
+            end = buf + len;
+
+            /* look for sps and pps */
+            while (buf < end) {
+                unsigned int size;
+                uint8_t nal_type;
+                size = AV_RB32(buf);
+                nal_type = buf[4] & 0x1f;
+                if (nal_type == 7) { /* SPS */
+                    sps = buf + 4;
+                    sps_size = size;
+                } else if (nal_type == 8) { /* PPS */
+                    pps = buf + 4;
+                    pps_size = size;
+                }
+                buf += size + 4;
+            }
+            assert(sps);
+            assert(pps);
+
+            put_byte(pb, 1); /* version */
+            put_byte(pb, sps[1]); /* profile */
+            put_byte(pb, sps[2]); /* profile compat */
+            put_byte(pb, sps[3]); /* level */
+            put_byte(pb, 0xff); /* 6 bits reserved (111111) + 2 bits nal size length - 1 (11) */
+            put_byte(pb, 0xe1); /* 3 bits reserved (111) + 5 bits number of sps (00001) */
+
+            put_be16(pb, sps_size);
+            put_buffer(pb, sps, sps_size);
+            put_byte(pb, 1); /* number of pps */
+            put_be16(pb, pps_size);
+            put_buffer(pb, pps, pps_size);
+            av_free(data);
+        } else {
+            put_buffer(pb, data, len);
+        }
+    }
+    return 0;
+}
-- 
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