Import minimal set of code from h264bitstream needed for SPS fixups

2026-08-27 04:37:41 +00:00 · 2026-07-26 18:09:53 -05:00
parent 2fc0d84aa0
commit b7adc70ea4
9 changed files with 1590 additions and 16 deletions
@@ -0,0 +1,147 @@
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "h264_stream.h"
+
+h264_stream_t* h264_new()
+{
+    h264_stream_t* h = (h264_stream_t*)calloc(1, sizeof(h264_stream_t));
+    h->nal = (nal_t*)calloc(1, sizeof(nal_t));
+    h->sps = (sps_t*)calloc(1, sizeof(sps_t));
+    return h;
+}
+
+void h264_free(h264_stream_t* h)
+{
+    free(h->nal);
+    free(h->sps);
+    free(h);
+}
+
+int find_nal_unit(uint8_t* buf, int size, int* nal_start, int* nal_end)
+{
+    int i;
+    *nal_start = 0;
+    *nal_end = 0;
+
+    i = 0;
+    while (
+        (buf[i] != 0 || buf[i+1] != 0 || buf[i+2] != 0x01) &&
+        (buf[i] != 0 || buf[i+1] != 0 || buf[i+2] != 0 || buf[i+3] != 0x01)
+        )
+    {
+        i++;
+        if (i+4 >= size) { return 0; }
+    }
+
+    if  (buf[i] != 0 || buf[i+1] != 0 || buf[i+2] != 0x01)
+    {
+        i++;
+    }
+
+    if  (buf[i] != 0 || buf[i+1] != 0 || buf[i+2] != 0x01) { return 0; }
+    i+= 3;
+    *nal_start = i;
+
+    while (
+        (buf[i] != 0 || buf[i+1] != 0 || buf[i+2] != 0) &&
+        (buf[i] != 0 || buf[i+1] != 0 || buf[i+2] != 0x01)
+        )
+    {
+        i++;
+        if (i+3 >= size) { *nal_end = size; return -1; }
+    }
+
+    *nal_end = i;
+    return (*nal_end - *nal_start);
+}
+
+int rbsp_to_nal(const uint8_t* rbsp_buf, const int* rbsp_size, uint8_t* nal_buf, int* nal_size)
+{
+    int i;
+    int j     = 1;
+    int count = 0;
+
+    if (*nal_size > 0) { nal_buf[0] = 0x00; }
+
+    for ( i = 0; i < *rbsp_size ; )
+    {
+        if ( j >= *nal_size )
+        {
+            return -1;
+        }
+
+        if ( ( count == 2 ) && !(rbsp_buf[i] & 0xFC) )
+        {
+            nal_buf[j] = 0x03;
+            j++;
+            count = 0;
+            continue;
+        }
+        nal_buf[j] = rbsp_buf[i];
+        if ( rbsp_buf[i] == 0x00 )
+        {
+            count++;
+        }
+        else
+        {
+            count = 0;
+        }
+        i++;
+        j++;
+    }
+
+    *nal_size = j;
+    return j;
+}
+
+int nal_to_rbsp(const uint8_t* nal_buf, int* nal_size, uint8_t* rbsp_buf, int* rbsp_size)
+{
+    int i;
+    int j     = 0;
+    int count = 0;
+
+    for( i = 0; i < *nal_size; i++ )
+    {
+        if( ( count == 2 ) && ( nal_buf[i] < 0x03) )
+        {
+            return -1;
+        }
+
+        if( ( count == 2 ) && ( nal_buf[i] == 0x03) )
+        {
+            if((i < *nal_size - 1) && (nal_buf[i+1] > 0x03))
+            {
+                return -1;
+            }
+
+            if(i == *nal_size - 1)
+            {
+                break;
+            }
+
+            i++;
+            count = 0;
+        }
+
+        if ( j >= *rbsp_size )
+        {
+            return -1;
+        }
+
+        rbsp_buf[j] = nal_buf[i];
+        if(nal_buf[i] == 0x00)
+        {
+            count++;
+        }
+        else
+        {
+            count = 0;
+        }
+        j++;
+    }
+
+    *nal_size = i;
+    *rbsp_size = j;
+    return j;
+}