--- trunk/vfw/src/2pass.c	2002/04/06 06:21:29	105
+++ trunk/vfw/src/2pass.c	2002/07/27 21:38:19	343
@@ -23,6 +23,8 @@
  *
  *	History:
  *
+ *	17.04.2002	changed 1st pass quant to always be 2 (2pass_update())
+ *	07.04.2002	added max bitrate constraint, overflow controls (foxer)
  *	31.03.2002	inital version;
  *
  *************************************************************************/
@@ -161,6 +163,7 @@
 					{
 						i_boost_total = twopass->nns2.bytes * codec->config.keyframe_boost / 100;
 						i_total += twopass->nns2.bytes;
+						twopass->keyframe_locations[i_frames] = frames;
 						++i_frames;
 					}
 
@@ -172,6 +175,7 @@
 
 				++frames;
 			}
+			twopass->keyframe_locations[i_frames] = frames;
 
 			twopass->movie_curve = ((double)(total_ext + i_boost_total) / total_ext);
 			twopass->average_frame = ((double)(total_ext - i_total) / (frames - credits_frames - i_frames) / twopass->movie_curve);
@@ -369,6 +373,7 @@
 				{
 					i_total += twopass->nns1.bytes + twopass->nns1.bytes * codec->config.keyframe_boost / 100;
 					total += twopass->nns1.bytes * codec->config.keyframe_boost / 100;
+					twopass->keyframe_locations[i_frames] = frames;
 					++i_frames;
 				}
 
@@ -376,6 +381,7 @@
 
 				++frames;
 			}
+			twopass->keyframe_locations[i_frames] = frames;
 
 			// compensate for avi frame overhead
 			desired -= frames * 24;
@@ -680,6 +686,9 @@
 		}
 
 		twopass->overflow = 0;
+		twopass->KFoverflow = 0;
+		twopass->KFoverflow_partial = 0;
+		twopass->KF_idx = 1;
 
 		break;
 	}
@@ -700,6 +709,8 @@
 	int bytes1, bytes2;
 	int overflow;
 	int credits_pos;
+	int capped_to_max_framesize = 0;
+	int KFdistance, KF_min_size;
 
 	if (codec->framenum == 0)
 	{
@@ -919,6 +930,30 @@
 
 	twopass->desired_bytes2 = bytes2;
 
+	if (frame->intra)
+	{
+		KFdistance = codec->twopass.keyframe_locations[codec->twopass.KF_idx] -
+			codec->twopass.keyframe_locations[codec->twopass.KF_idx - 1];
+
+		if (KFdistance < codec->config.kftreshold)
+		{
+			KFdistance = KFdistance - codec->config.min_key_interval;
+
+			if (KFdistance >= 0)
+			{
+				KF_min_size = bytes2 * (100 - codec->config.kfreduction) / 100;
+				if (KF_min_size < 1)
+					KF_min_size = 1;
+
+				bytes2 = KF_min_size + (bytes2 - KF_min_size) * KFdistance /
+					(codec->config.kftreshold - codec->config.min_key_interval);
+
+				if (bytes2 < 1)
+					bytes2 = 1;
+			}
+		}
+	}
+
 	// Foxer: scale overflow in relation to average size, so smaller frames don't get
 	// too much/little bitrate
 	overflow = (int)((double)overflow * bytes2 / twopass->average_frame);
@@ -930,19 +965,26 @@
 	}
 
 	// Foxer: make sure overflow doesn't run away
-	if (overflow > bytes2 * 6 / 10)
+	if (overflow > bytes2 * codec->config.twopass_max_overflow_improvement / 100)
 	{
-		bytes2 += (overflow <= bytes2) ? bytes2 * 6 / 10 : overflow * 6 / 10;
+		bytes2 += (overflow <= bytes2) ? bytes2 * codec->config.twopass_max_overflow_improvement / 100 :
+			overflow * codec->config.twopass_max_overflow_improvement / 100;
 	}
-	else if (overflow < bytes2 * -6 / 10)
+	else if (overflow < bytes2 * codec->config.twopass_max_overflow_degradation / -100)
 	{
-		bytes2 += bytes2 * -6 / 10;
+		bytes2 += bytes2 * codec->config.twopass_max_overflow_degradation / -100;
 	}
 	else
 	{
 		bytes2 += overflow;
 	}
 
+	if (bytes2 > twopass->max_framesize)
+	{
+		capped_to_max_framesize = 1;
+		bytes2 = twopass->max_framesize;
+	}
+
 	if (bytes2 < 1) 
 	{
 		bytes2 = 1;
@@ -1006,7 +1048,7 @@
 		}
 
 		// subsequent frame quants can only be +- 2
-		if (last_quant)
+		if (last_quant && capped_to_max_framesize == 0)
 		{
 			if (frame->quant > last_quant + 2)
 			{
@@ -1021,7 +1063,8 @@
 		}
 	}
 
-	last_quant = frame->quant;
+	if (capped_to_max_framesize == 0)
+		last_quant = frame->quant;
 
 	if (codec->config.quant_type == QUANT_MODE_MOD)
 	{
@@ -1039,7 +1082,7 @@
 
 	NNSTATS nns1;
 	DWORD wrote;
-	int credits_pos;
+	int credits_pos, tempdiv;
 	char* quant_type;
 
 	if (codec->framenum == 0)
@@ -1062,7 +1105,8 @@
 		nns1.md_u = nns1.md_y = 0;
 		nns1.mk_u = nns1.mk_y = 0;
 
-		nns1.quant = stats->quant;
+//		nns1.quant = stats->quant;
+		nns1.quant = 2;				// ugly fix for lumi masking in 1st pass returning new quant
 		if (frame->intra) 
 		{
 			nns1.quant |= NNSTATS_KEYFRAME;
@@ -1085,11 +1129,49 @@
 
 	case DLG_MODE_2PASS_2_INT :
 	case DLG_MODE_2PASS_2_EXT :
-		codec->twopass.overflow += codec->twopass.desired_bytes2 - frame->length;
-
 		credits_pos = codec_is_in_credits(&codec->config, codec->framenum);
 		if (!credits_pos)
+		{
 			codec->twopass.quant_count[frame->quant]++;
+			if ((codec->twopass.nns1.quant & NNSTATS_KEYFRAME))
+			{
+				codec->twopass.overflow += codec->twopass.KFoverflow;
+				codec->twopass.KFoverflow = codec->twopass.desired_bytes2 - frame->length;
+
+				tempdiv = (codec->twopass.keyframe_locations[codec->twopass.KF_idx] -
+					codec->twopass.keyframe_locations[codec->twopass.KF_idx - 1]);
+
+				if (tempdiv > 1)
+				{
+					// non-consecutive keyframes
+					codec->twopass.KFoverflow_partial = codec->twopass.KFoverflow / (tempdiv - 1);
+				}
+				else
+				{
+					// consecutive keyframes
+					codec->twopass.overflow += codec->twopass.KFoverflow;
+					codec->twopass.KFoverflow = 0;
+					codec->twopass.KFoverflow_partial = 0;
+				}
+				codec->twopass.KF_idx++;
+			}
+			else
+			{
+				codec->twopass.overflow += codec->twopass.desired_bytes2 - frame->length +
+					codec->twopass.KFoverflow_partial;
+				codec->twopass.KFoverflow -= codec->twopass.KFoverflow_partial;
+			}
+		}
+		else
+		{
+			codec->twopass.overflow += codec->twopass.desired_bytes2 - frame->length;
+
+			// ugly fix for credits..
+			codec->twopass.overflow += codec->twopass.KFoverflow;
+			codec->twopass.KFoverflow = 0;
+			codec->twopass.KFoverflow_partial = 0;
+			// end of ugly fix.
+		}
 
 		DEBUG2ND(frame->quant, quant_type, frame->intra, codec->twopass.bytes1, codec->twopass.desired_bytes2, frame->length, codec->twopass.overflow, credits_pos)
 		break;