xvid_vbr.c

自己移植的linux下的流媒体播放器原代码,支持mms协议,支持ftp和http协议.

				{
					oldquant = newquant;
					percent = (int)((n - state->average_frame) * 100.0 / state->average_frame);
				}

			}
		      
		}

	}

	state->overflow = 0;
	state->KFoverflow = 0;
	state->KFoverflow_partial = 0;
	state->KF_idx = 1;

	for (n=0 ; n < 32 ; n++) {
		state->quant_error[n] = 0.0;
		state->quant_count[n] = 0;
	}

	state->curve_comp_error = 0.0;
	state->last_quant = 0;

	/*
	 * Above this frame size limit, normal vbr rules will not apply
	 * This means :
	 *      1 - Quant can de/increase more than -/+2 between 2 frames
	 *      2 - Leads to artifacts because of 1
	 */
	state->max_framesize = state->twopass_max_bitrate/state->fps;

	/* Get back to the beginning of frame statistics */
	fseek(state->pass1_file, pos_firstframe, SEEK_SET);

	/* 
	 * Small hack : We have to get next frame stats before the
	 * getintra/quant calls
	 * User clients update the data when they call vbrUpdate
	 * we are just bypassing this because we don't have to update
	 * the overflow and so on...
	 */
	{

		/* Fake vars */
		int next_hbytes, next_kblocks, next_mblocks, next_ublocks;
 
		fscanf(state->pass1_file, "%d %d %d %d %d %d %d\n",
		       &state->pass1_quant, &state->pass1_intra, &next_hbytes,
		       &state->pass1_bytes, &next_kblocks, &next_mblocks,
		       &next_ublocks);

	}

	/* Initialize the frame counter */
	state->cur_frame = 0;
	state->last_keyframe = 0;

	return(0);

}

static int vbr_getquant_2pass2(void *sstate)
{

	int quant;
	int intra;
	int bytes1, bytes2;
	int overflow;
	int capped_to_max_framesize = 0;
	int KFdistance, KF_min_size;
	vbr_control_t *state = sstate;

	bytes1 = state->pass1_bytes;
	overflow = state->overflow / 8;
	/* To shut up gcc warning */
	bytes2 = bytes1;


	if (state->pass1_intra)
	{
		overflow = 0;
	}

	if (util_frametype(state) != FRAME_TYPE_NORMAL_MOVIE) {


		switch (state->credits_mode) {
		case VBR_CREDITS_MODE_QUANT :
			if (state->credits_quant_i != state->credits_quant_p) {
				quant = state->pass1_intra ?
					state->credits_quant_i:
					state->credits_quant_p;
			}
			else {
				quant = state->credits_quant_p;
			}

			state->bytes1 = bytes1;
			state->bytes2 = bytes1;
			state->desired_bytes2 = bytes1;
			return(quant);
		default:
		case VBR_CREDITS_MODE_RATE :
		case VBR_CREDITS_MODE_SIZE :
			if(util_frametype(state) == FRAME_TYPE_STARTING_CREDITS)
				bytes2 = (int)(bytes1 / state->credits_start_curve);
			else
				bytes2 = (int)(bytes1 / state->credits_end_curve);
			break;
		}
	}
	else {
		/* Foxer: apply curve compression outside credits */
		double dbytes, curve_temp;

		bytes2 = bytes1;

		if (state->pass1_intra)
			dbytes = ((int)(bytes2 + bytes2 * state->keyframe_boost / 100)) /
				state->movie_curve;
		else
			dbytes = bytes2 / state->movie_curve;

		/* spread the compression error accross payback_delay frames */
		if (state->bitrate_payback_method == VBR_PAYBACK_BIAS)	{
			bytes2 = (int)(state->curve_comp_error / state->bitrate_payback_delay);
		}
		else {
			bytes2 = (int)(state->curve_comp_error * dbytes /
				state->average_frame / state->bitrate_payback_delay);

			if (labs(bytes2) > fabs(state->curve_comp_error))
				bytes2 = (int)state->curve_comp_error;
		}

		state->curve_comp_error -= bytes2;

		if (state->use_alt_curve) {

			if (!state->pass1_intra) {

				if (dbytes > state->average_frame) {
					if (dbytes >= state->alt_curve_high)
						curve_temp = dbytes * (state->alt_curve_mid_qual - state->alt_curve_qual_dev);
					else {
						switch(state->alt_curve_type) {
						case VBR_ALT_CURVE_AGGRESIVE:
							curve_temp = dbytes * (state->alt_curve_mid_qual - state->alt_curve_qual_dev *
									       sin(DEG2RAD * ((dbytes - state->average_frame) * 90.0 / state->alt_curve_high_diff)));
							break;
						default:
						case VBR_ALT_CURVE_LINEAR:
							curve_temp = dbytes * (state->alt_curve_mid_qual - state->alt_curve_qual_dev *
									       (dbytes - state->average_frame) / state->alt_curve_high_diff);
							break;
						case VBR_ALT_CURVE_SOFT:
							curve_temp = dbytes * (state->alt_curve_mid_qual - state->alt_curve_qual_dev *
									       (1.0 - cos(DEG2RAD * ((dbytes - state->average_frame) * 90.0 / state->alt_curve_high_diff))));
						}
					}
				}
				else {
					if (dbytes <= state->alt_curve_low)
						curve_temp = dbytes;
					else {
						switch(state->alt_curve_type) {
						case VBR_ALT_CURVE_AGGRESIVE:
							curve_temp = dbytes * (state->alt_curve_mid_qual - state->alt_curve_qual_dev *
									       sin(DEG2RAD * ((dbytes - state->average_frame) * 90.0 / state->alt_curve_low_diff)));
							break;
						default:
						case VBR_ALT_CURVE_LINEAR:
							curve_temp = dbytes * (state->alt_curve_mid_qual - state->alt_curve_qual_dev *
									       (dbytes - state->average_frame) / state->alt_curve_low_diff);
							break;
						case VBR_ALT_CURVE_SOFT:
							curve_temp = dbytes * (state->alt_curve_mid_qual + state->alt_curve_qual_dev *
									       (1.0 - cos(DEG2RAD * ((dbytes - state->average_frame) * 90.0 / state->alt_curve_low_diff))));
						}
					}
				}

				curve_temp = curve_temp * state->curve_comp_scale + state->curve_bias_bonus;

				bytes2 += ((int)curve_temp);
				state->curve_comp_error += curve_temp - ((int)curve_temp);

			}
			else {
				state->curve_comp_error += dbytes - ((int)dbytes);
				bytes2 += ((int)dbytes);
			}
		}
		else if ((state->curve_compression_high + state->curve_compression_low) &&
			!state->pass1_intra) {

			if (dbytes > state->average_frame) {
				curve_temp = state->curve_comp_scale *
					((double)dbytes + (state->average_frame - dbytes) *
					state->curve_compression_high / 100.0);
			}
			else {
				curve_temp = state->curve_comp_scale *
					((double)dbytes + (state->average_frame - dbytes) *
					state->curve_compression_low / 100.0);
			}

			bytes2 += ((int)curve_temp);
			state->curve_comp_error += curve_temp - ((int)curve_temp);
		}
		else {
			state->curve_comp_error += dbytes - ((int)dbytes);
			bytes2 += ((int)dbytes);
		}

		/* cap bytes2 to first pass size, lowers number of quant=1 frames */
		if (bytes2 > bytes1) {
			state->curve_comp_error += bytes2 - bytes1;
			bytes2 = bytes1;
		}
		else if (bytes2 < 1) {
			state->curve_comp_error += --bytes2;
			bytes2 = 1;
		}
	}

	state->desired_bytes2 = bytes2;

	/* Ugly dependance between getquant and getintra */
	intra = state->getintra(state);

	if(intra) {

		KFdistance = state->keyframe_locations[state->KF_idx] -
			state->keyframe_locations[state->KF_idx - 1];

		if (KFdistance < state->kftreshold) {
			KFdistance = KFdistance - state->min_key_interval;

			if (KFdistance >= 0) {

				KF_min_size = bytes2 * (100 - state->kfreduction) / 100;
				if (KF_min_size < 1)
					KF_min_size = 1;

				bytes2 = KF_min_size + (bytes2 - KF_min_size) * KFdistance /
					(state->kftreshold - state->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 / state->average_frame);

	/* Foxer: reign in overflow with huge frames */
	if (labs(overflow) > labs(state->overflow)) {
		overflow = state->overflow;
	}

	/* Foxer: make sure overflow doesn't run away */
	if(overflow > bytes2 * state->twopass_max_overflow_improvement / 100) {
		bytes2 += (overflow <= bytes2) ? bytes2 * state->twopass_max_overflow_improvement / 100 :
			overflow * state->twopass_max_overflow_improvement / 100;
	}
	else if(overflow < bytes2 * state->twopass_max_overflow_degradation / -100) {
		bytes2 += bytes2 * state->twopass_max_overflow_degradation / -100;
	}
	else {
		bytes2 += overflow;
	}

	if(bytes2 > state->max_framesize) {
		capped_to_max_framesize = 1;
		bytes2 = state->max_framesize;
	}

	if(bytes2 < 1) {
		bytes2 = 1;
	}

	state->bytes1 = bytes1;
	state->bytes2 = bytes2;

	/* very 'simple' quant<->filesize relationship */
	quant = state->pass1_quant * bytes1 / bytes2;

	if(quant < 1)
		quant = 1;
	else if(quant > 31)
		quant = 31;
	else if(!state->pass1_intra) {

		/* Foxer: aid desired quantizer precision by accumulating decision error */
		state->quant_error[quant] += ((double)(state->pass1_quant * bytes1) / bytes2) - quant;

		if (state->quant_error[quant] >= 1.0) {
			state->quant_error[quant] -= 1.0;
			quant++;
		}
	}

	/* we're done with credits */
	if(util_frametype(state) != FRAME_TYPE_NORMAL_MOVIE) {
		return(quant);
	}

	if(intra) {

		if (quant < state->min_iquant)
			quant = state->min_iquant;
		if (quant > state->max_iquant)
			quant = state->max_iquant;
	}
	else {

		if(quant > state->max_pquant)
			quant = state->max_pquant;
		if(quant < state->min_pquant)
			quant = state->min_pquant;

		/* subsequent frame quants can only be +- 2 */
		if(state->last_quant && capped_to_max_framesize == 0) {
			if (quant > state->last_quant + 2)
				quant = state->last_quant + 2;
			if (quant < state->last_quant - 2)
				quant = state->last_quant - 2;
		}
	}

	return(quant);

}

static int vbr_getintra_2pass2(void *sstate)
{

	int intra;
	vbr_control_t *state = sstate;

	
	/* Get next intra state (fetched by update) */
	intra = state->pass1_intra;

	/* During credits, XviD will decide itself */
	if(util_frametype(state) != FRAME_TYPE_NORMAL_MOVIE) {


		switch(state->credits_mode) {
		default:
		case VBR_CREDITS_MODE_RATE :
		case VBR_CREDITS_MODE_SIZE :
			intra = -1;
			break;
		case VBR_CREDITS_MODE_QUANT :
			/* Except in this case */
			if (state->credits_quant_i == state->credits_quant_p)
				intra = -1;
			break;
		}

	}

	/* Force I Frame when max_key_interval is reached */
	if((state->cur_frame - state->last_keyframe) > state->max_key_interval)
		intra = 1;

	/*
	 * Force P or B Frames for frames whose distance is less than the
	 * requested minimum
	 */
	if((state->cur_frame - state->last_keyframe) < state->min_key_interval)
		intra = 0;


	/* Return the given intra mode except for first frame */
	return((state->cur_frame==0)?1:intra);

}

static int vbr_update_2pass2(void *sstate,
			     int quant,
			     int intra,
			     int header_bytes,
			     int total_bytes,
			     int kblocks,
			     int mblocks,
			     int ublocks)
			     

{


	int next_hbytes, next_kblocks, next_mblocks, next_ublocks;
	int tempdiv;

	vbr_control_t *state = sstate;

	/*
	 * We do not depend on getintra/quant because we have the real results
	 * from the xvid core
	 */

	if (util_frametype(state) == FRAME_TYPE_NORMAL_MOVIE) {

		state->quant_count[quant]++;

		if (state->pass1_intra) {

			state->overflow += state->KFoverflow;
			state->KFoverflow = state->desired_bytes2 - total_bytes;

			tempdiv = (state->keyframe_locations[state->KF_idx] -
				   state->keyframe_locations[state->KF_idx - 1]);

			/* redistribute correctly (by koepi) */
			if (tempdiv > 1) {
				/* non-consecutive keyframes */
				state->KFoverflow_partial = state->KFoverflow /
					(tempdiv - 1);
			}
			else {
				state->overflow  += state->KFoverflow;
				state->KFoverflow = 0;
				state->KFoverflow_partial = 0;
			}
			state->KF_idx++;

		}
		else {
			state->overflow += state->desired_bytes2 - total_bytes +
				state->KFoverflow_partial;
			state->KFoverflow -= state->KFoverflow_partial;
		}
	}
	else {

		state->overflow += state->desired_bytes2 - total_bytes;
		state->overflow += state->KFoverflow;
		state->KFoverflow = 0;
		state->KFoverflow_partial = 0;
	}

	/* Save old quant */
	state->last_quant = quant;

	/* Update next frame data */
	fscanf(state->pass1_file, "%d %d %d %d %d %d %d\n",
	       &state->pass1_quant, &state->pass1_intra, &next_hbytes,
	       &state->pass1_bytes, &next_kblocks, &next_mblocks,
	       &next_ublocks);

	/* Save the last Keyframe pos */
	if(intra)
		state->last_keyframe = state->cur_frame;

	/* Ok next frame */
	state->cur_frame++;
	   
	return(0);

}

static int vbr_finish_2pass2(void *sstate)
{

	vbr_control_t *state = sstate;

	if(state->pass1_file == NULL)
		return(-1);

	/* Close the file */
	if(fclose(state->pass1_file) != 0)
		return(-1);

	/* Free the memory */
	if(state->keyframe_locations)
		free(state->keyframe_locations);

	return(0);

}


/******************************************************************************
 * Fixed quant mode - Most of the functions will be dummy functions
 *****************************************************************************/

static int vbr_init_fixedquant(void *sstate)
{

	vbr_control_t *state = sstate;

	if(state->fixed_quant < 1)
		state->fixed_quant = 1;

	if(state->fixed_quant > 31)
		state->fixed_quant = 31;

	state->cur_frame = 0;

	return(0);

}

static int vbr_getquant_fixedquant(void *sstate)
{

	vbr_control_t *state = sstate;

	/* Credits' frame ? */
	if(util_frametype(state) != FRAME_TYPE_NORMAL_MOVIE) {

		int quant;

		switch(state->credits_mode) {
		case VBR_CREDITS_MODE_RATE:
			quant = state->fixed_quant * state->credits_quant_ratio;
			break;
		case VBR_CREDITS_MODE_QUANT:
			quant = state->credits_fixed_quant;
			break;
		default:
			quant = state->fixed_quant;

		}

		return(quant);

	}
		
	/* No credit frame - return fixed quant */
	return(state->fixed_quant);

}

static int vbr_getintra_fixedquant(void *state)
{

	return(-1);

}