Add checksum SEI packages to the bit-stream.

src/encoder.c

@@ -34,6 +34,9 @@
 int16_t g_lambda_cost[55];
 uint32_t* g_auiSigLastScan[3][7];
 
+/* Local functions. */
+static void add_checksum(encoder_control* encoder);
+
 void initSigLastScan(uint32_t* pBuffD, uint32_t* pBuffH, uint32_t* pBuffV, int32_t iWidth, int32_t iHeight)
 {
   uint32_t uiNumScanPos  = iWidth * iWidth;
@@ -370,6 +373,8 @@ void encode_one_frame(encoder_control* encoder)
     filter_deblock(encoder);
   }
 
+  /* Calculate checksum */
+  add_checksum(encoder);
 
   /* Clear prediction data */
   /* ToDo: store as reference data */
@@ -380,6 +385,37 @@ void encode_one_frame(encoder_control* encoder)
 
 }
 
+
+/*!
+ \brief Add a checksum SEI message to the bitstream.
+ \param encoder The encoder.
+ \returns Void
+ */
+static void add_checksum(encoder_control* encoder)
+{
+  unsigned char checksum[3][16];
+  uint32_t checksum_val;
+  unsigned int i;
+
+  picture_checksum(&(encoder->in.cur_pic), checksum);
+
+  WRITE_U(encoder->stream, 132, 8, "sei_type");
+  WRITE_U(encoder->stream, 13, 8, "size");
+  WRITE_U(encoder->stream, 2, 8, "hash_type"); /* 2 = checksum*/
+
+  for (i = 0; i < 3; ++i) {
+    /* Pack bits into a single 32 bit uint instead of pushing them one byte at a time. */
+    checksum_val = (checksum[i][0] << 24) + (checksum[i][1] << 16) + (checksum[i][2] << 8) + (checksum[i][3]);
+    WRITE_U(encoder->stream, checksum_val, 32, 'picture_checksum');
+  }
+
+  bitstream_align(encoder->stream);
+  bitstream_flush(encoder->stream);
+  nal_write(encoder->output, encoder->stream->buffer, encoder->stream->buffer_pos, 0, NAL_SUFFIT_SEI_NUT, 0);
+  bitstream_clear_buffer(encoder->stream);
+}
+
+
 void encode_pic_parameter_set(encoder_control* encoder)
 {
 #ifdef _DEBUG

src/nal.c

@@ -85,4 +85,50 @@ void nal_write(FILE* output, uint8_t* buffer, uint32_t buffer_len, uint8_t nal_r
     fwrite(&emulation_prevention_three_byte, 1, 1, output);
   }
 
+}
+
+
+/*!
+ \brief Calculate checksum for one color of the picture.
+ \param data Beginning of the pixel data for the picture.
+ \param height Height of the picture.
+ \param width Width of the picture.
+ \param stride Width of one row in the pixel array.
+ \returns Void
+*/
+static void array_checksum(uint8_t* data, const int height, const int width, const int stride, unsigned char checksum_out[])
+{
+	unsigned char mask;
+	unsigned int checksum = 0;
+	int y, x;
+	for (y = 0; y < height; ++y) {
+		for (x = 0; x < width; ++x) {
+			mask = (x & 0xff) ^ (y & 0xff) ^ (x >> 8) ^ (y >> 8);
+			checksum += (data[(y * stride) + x] & 0xff) ^ mask;
+			checksum &= 0xffffffff;
+		}
+	}
+
+  /* Unpack uint into byte-array.*/
+	checksum_out[0] = (checksum >> 24) & 0xff;
+	checksum_out[1] = (checksum >> 16) & 0xff;
+	checksum_out[2] = (checksum >> 8) & 0xff;
+	checksum_out[3] = (checksum) & 0xff;
+}
+
+
+/*!
+ \brief Calculate checksums for all colors of the picture.
+ \param pic The picture that checksum is calculated for.
+ \param checksum_out Result of the calculation.
+ \returns Void
+*/
+void picture_checksum(const picture* pic, unsigned char checksum_out[][16])
+{
+	int stride = pic->width; /* ToDo: != width, if there is a luma margin. */
+	array_checksum(pic->yRecData, pic->height, pic->width, pic->width, checksum_out[0]);
+
+  /* The number of chroma pixels is half that of luma. */
+	array_checksum(pic->uRecData, pic->height >> 1, pic->width >> 1, pic->width >> 1, checksum_out[1]);
+	array_checksum(pic->vRecData, pic->height >> 1, pic->width >> 1, pic->width >> 1, checksum_out[2]);
 }

src/nal.h

@@ -22,9 +22,11 @@ enum { NAL_TRAIL_N    = 0, NAL_TRAIL_R    = 1,
        NAL_RSV_IRAP_VCL23 = 23,
 
        /* Parameter sets */       
-       NAL_VID_PARAMETER_SET = 32, NAL_SEQ_PARAMETER_SET = 33, NAL_PIC_PARAMETER_SET = 34
+       NAL_VID_PARAMETER_SET = 32, NAL_SEQ_PARAMETER_SET = 33, NAL_PIC_PARAMETER_SET = 34,
+       NAL_SUFFIT_SEI_NUT = 40
 };
 
 void nal_write(FILE* output, uint8_t* buffer, uint32_t buffer_len, uint8_t nal_ref, uint8_t nal_type, uint8_t temporal_id);
+void picture_checksum(const picture* pic, unsigned char* checksum_out);
 
 #endif