libavcodec/vorbis.c - nest-android-app/ffmpeg - Git at Google

 /**
  * @file
  * Common code for Vorbis I encoder and decoder
  * @author Denes Balatoni  ( dbalatoni programozo hu )
  *
  * 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
  */

 /**
  * @file
  * Common code for Vorbis I encoder and decoder
  * @author Denes Balatoni  ( dbalatoni programozo hu )
  */

 #define BITSTREAM_READER_LE
 #include "avcodec.h"
 #include "get_bits.h"

 #include "vorbis.h"


 /* Helper functions */

 // x^(1/n)
 unsigned int ff_vorbis_nth_root(unsigned int x, unsigned int n)
 {
     unsigned int ret = 0, i, j;

     do {
         ++ret;
         for (i = 0, j = ret; i < n - 1; i++)
             j *= ret;
     } while (j <= x);

     return ret - 1;
 }

 // Generate vlc codes from vorbis huffman code lengths

 // the two bits[p] > 32 checks should be redundant, all calling code should
 // already ensure that, but since it allows overwriting the stack it seems
 // reasonable to check redundantly.
 int ff_vorbis_len2vlc(uint8_t *bits, uint32_t *codes, unsigned num)
 {
     uint32_t exit_at_level[33] = { 404 };

     unsigned i, j, p, code;

 #ifdef DEBUG
     GetBitContext gb;
 #endif

     for (p = 0; (bits[p] == 0) && (p < num); ++p)
         ;
     if (p == num)
         return 0;

     codes[p] = 0;
     if (bits[p] > 32)
         return AVERROR_INVALIDDATA;
     for (i = 0; i < bits[p]; ++i)
         exit_at_level[i+1] = 1 << i;

 #ifdef DEBUG
     av_log(NULL, AV_LOG_INFO, " %u. of %u code len %d code %d - ", p, num, bits[p], codes[p]);
     init_get_bits(&gb, (uint8_t *)&codes[p], bits[p]);
     for (i = 0; i < bits[p]; ++i)
         av_log(NULL, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0");
     av_log(NULL, AV_LOG_INFO, "\n");
 #endif

     ++p;

     for (i = p; (bits[i] == 0) && (i < num); ++i)
         ;
     if (i == num)
         return 0;

     for (; p < num; ++p) {
         if (bits[p] > 32)
              return AVERROR_INVALIDDATA;
         if (bits[p] == 0)
              continue;
         // find corresponding exit(node which the tree can grow further from)
         for (i = bits[p]; i > 0; --i)
             if (exit_at_level[i])
                 break;
         if (!i) // overspecified tree
              return AVERROR_INVALIDDATA;
         code = exit_at_level[i];
         exit_at_level[i] = 0;
         // construct code (append 0s to end) and introduce new exits
         for (j = i + 1 ;j <= bits[p]; ++j)
             exit_at_level[j] = code + (1 << (j - 1));
         codes[p] = code;

 #ifdef DEBUG
         av_log(NULL, AV_LOG_INFO, " %d. code len %d code %d - ", p, bits[p], codes[p]);
         init_get_bits(&gb, (uint8_t *)&codes[p], bits[p]);
         for (i = 0; i < bits[p]; ++i)
             av_log(NULL, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0");
         av_log(NULL, AV_LOG_INFO, "\n");
 #endif

     }

     //no exits should be left (underspecified tree - ie. unused valid vlcs - not allowed by SPEC)
     for (p = 1; p < 33; p++)
         if (exit_at_level[p])
             return AVERROR_INVALIDDATA;

     return 0;
 }

 int ff_vorbis_ready_floor1_list(AVCodecContext *avctx,
                                 vorbis_floor1_entry *list, int values)
 {
     int i;
     list[0].sort = 0;
     list[1].sort = 1;
     for (i = 2; i < values; i++) {
         int j;
         list[i].low  = 0;
         list[i].high = 1;
         list[i].sort = i;
         for (j = 2; j < i; j++) {
             int tmp = list[j].x;
             if (tmp < list[i].x) {
                 if (tmp > list[list[i].low].x)
                     list[i].low  =  j;
             } else {
                 if (tmp < list[list[i].high].x)
                     list[i].high = j;
             }
         }
     }
     for (i = 0; i < values - 1; i++) {
         int j;
         for (j = i + 1; j < values; j++) {
             if (list[i].x == list[j].x) {
                 av_log(avctx, AV_LOG_ERROR,
                        "Duplicate value found in floor 1 X coordinates\n");
                 return AVERROR_INVALIDDATA;
             }
             if (list[list[i].sort].x > list[list[j].sort].x) {
                 int tmp = list[i].sort;
                 list[i].sort = list[j].sort;
                 list[j].sort = tmp;
             }
         }
     }
     return 0;
 }

 static inline void render_line_unrolled(intptr_t x, int y, int x1,
                                         intptr_t sy, int ady, int adx,
                                         float *buf)
 {
     int err = -adx;
     x -= x1 - 1;
     buf += x1 - 1;
     while (++x < 0) {
         err += ady;
         if (err >= 0) {
             err += ady - adx;
             y   += sy;
             buf[x++] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)];
         }
         buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)];
     }
     if (x <= 0) {
         if (err + ady >= 0)
             y += sy;
         buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)];
     }
 }

 static void render_line(int x0, int y0, int x1, int y1, float *buf)
 {
     int dy  = y1 - y0;
     int adx = x1 - x0;
     int ady = FFABS(dy);
     int sy  = dy < 0 ? -1 : 1;
     buf[x0] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y0)];
     if (ady*2 <= adx) { // optimized common case
         render_line_unrolled(x0, y0, x1, sy, ady, adx, buf);
     } else {
         int base  = dy / adx;
         int x     = x0;
         int y     = y0;
         int err   = -adx;
         ady -= FFABS(base) * adx;
         while (++x < x1) {
             y += base;
             err += ady;
             if (err >= 0) {
                 err -= adx;
                 y   += sy;
             }
             buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)];
         }
     }
 }

 void ff_vorbis_floor1_render_list(vorbis_floor1_entry * list, int values,
                                   uint16_t *y_list, int *flag,
                                   int multiplier, float *out, int samples)
 {
     int lx, ly, i;
     lx = 0;
     ly = y_list[0] * multiplier;
     for (i = 1; i < values; i++) {
         int pos = list[i].sort;
         if (flag[pos]) {
             int x1 = list[pos].x;
             int y1 = y_list[pos] * multiplier;
             if (lx < samples)
                 render_line(lx, ly, FFMIN(x1,samples), y1, out);
             lx = x1;
             ly = y1;
         }
         if (lx >= samples)
             break;
     }
     if (lx < samples)
         render_line(lx, ly, samples, ly, out);
 }
	/**
	* @file
	* Common code for Vorbis I encoder and decoder
	* @author Denes Balatoni ( dbalatoni programozo hu )
	*
	* 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
	*/

	/**
	* @file
	* Common code for Vorbis I encoder and decoder
	* @author Denes Balatoni ( dbalatoni programozo hu )
	*/

	#define BITSTREAM_READER_LE
	#include "avcodec.h"
	#include "get_bits.h"

	#include "vorbis.h"


	/* Helper functions */

	// x^(1/n)
	unsigned int ff_vorbis_nth_root(unsigned int x, unsigned int n)
	{
	unsigned int ret = 0, i, j;

	do {
	++ret;
	for (i = 0, j = ret; i < n - 1; i++)
	j *= ret;
	} while (j <= x);

	return ret - 1;
	}

	// Generate vlc codes from vorbis huffman code lengths

	// the two bits[p] > 32 checks should be redundant, all calling code should
	// already ensure that, but since it allows overwriting the stack it seems
	// reasonable to check redundantly.
	int ff_vorbis_len2vlc(uint8_t bits, uint32_t codes, unsigned num)
	{
	uint32_t exit_at_level[33] = { 404 };

	unsigned i, j, p, code;

	#ifdef DEBUG
	GetBitContext gb;
	#endif

	for (p = 0; (bits[p] == 0) && (p < num); ++p)
	;
	if (p == num)
	return 0;

	codes[p] = 0;
	if (bits[p] > 32)
	return AVERROR_INVALIDDATA;
	for (i = 0; i < bits[p]; ++i)
	exit_at_level[i+1] = 1 << i;

	#ifdef DEBUG
	av_log(NULL, AV_LOG_INFO, " %u. of %u code len %d code %d - ", p, num, bits[p], codes[p]);
	init_get_bits(&gb, (uint8_t *)&codes[p], bits[p]);
	for (i = 0; i < bits[p]; ++i)
	av_log(NULL, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0");
	av_log(NULL, AV_LOG_INFO, "\n");
	#endif

	++p;

	for (i = p; (bits[i] == 0) && (i < num); ++i)
	;
	if (i == num)
	return 0;

	for (; p < num; ++p) {
	if (bits[p] > 32)
	return AVERROR_INVALIDDATA;
	if (bits[p] == 0)
	continue;
	// find corresponding exit(node which the tree can grow further from)
	for (i = bits[p]; i > 0; --i)
	if (exit_at_level[i])
	break;
	if (!i) // overspecified tree
	return AVERROR_INVALIDDATA;
	code = exit_at_level[i];
	exit_at_level[i] = 0;
	// construct code (append 0s to end) and introduce new exits
	for (j = i + 1 ;j <= bits[p]; ++j)
	exit_at_level[j] = code + (1 << (j - 1));
	codes[p] = code;

	#ifdef DEBUG
	av_log(NULL, AV_LOG_INFO, " %d. code len %d code %d - ", p, bits[p], codes[p]);
	init_get_bits(&gb, (uint8_t *)&codes[p], bits[p]);
	for (i = 0; i < bits[p]; ++i)
	av_log(NULL, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0");
	av_log(NULL, AV_LOG_INFO, "\n");
	#endif

	}

	//no exits should be left (underspecified tree - ie. unused valid vlcs - not allowed by SPEC)
	for (p = 1; p < 33; p++)
	if (exit_at_level[p])
	return AVERROR_INVALIDDATA;

	return 0;
	}

	int ff_vorbis_ready_floor1_list(AVCodecContext *avctx,
	vorbis_floor1_entry *list, int values)
	{
	int i;
	list[0].sort = 0;
	list[1].sort = 1;
	for (i = 2; i < values; i++) {
	int j;
	list[i].low = 0;
	list[i].high = 1;
	list[i].sort = i;
	for (j = 2; j < i; j++) {
	int tmp = list[j].x;
	if (tmp < list[i].x) {
	if (tmp > list[list[i].low].x)
	list[i].low = j;
	} else {
	if (tmp < list[list[i].high].x)
	list[i].high = j;
	}
	}
	}
	for (i = 0; i < values - 1; i++) {
	int j;
	for (j = i + 1; j < values; j++) {
	if (list[i].x == list[j].x) {
	av_log(avctx, AV_LOG_ERROR,
	"Duplicate value found in floor 1 X coordinates\n");
	return AVERROR_INVALIDDATA;
	}
	if (list[list[i].sort].x > list[list[j].sort].x) {
	int tmp = list[i].sort;
	list[i].sort = list[j].sort;
	list[j].sort = tmp;
	}
	}
	}
	return 0;
	}

	static inline void render_line_unrolled(intptr_t x, int y, int x1,
	intptr_t sy, int ady, int adx,
	float *buf)
	{
	int err = -adx;
	x -= x1 - 1;
	buf += x1 - 1;
	while (++x < 0) {
	err += ady;
	if (err >= 0) {
	err += ady - adx;
	y += sy;
	buf[x++] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)];
	}
	buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)];
	}
	if (x <= 0) {
	if (err + ady >= 0)
	y += sy;
	buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)];
	}
	}

	static void render_line(int x0, int y0, int x1, int y1, float *buf)
	{
	int dy = y1 - y0;
	int adx = x1 - x0;
	int ady = FFABS(dy);
	int sy = dy < 0 ? -1 : 1;
	buf[x0] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y0)];
	if (ady*2 <= adx) { // optimized common case
	render_line_unrolled(x0, y0, x1, sy, ady, adx, buf);
	} else {
	int base = dy / adx;
	int x = x0;
	int y = y0;
	int err = -adx;
	ady -= FFABS(base) * adx;
	while (++x < x1) {
	y += base;
	err += ady;
	if (err >= 0) {
	err -= adx;
	y += sy;
	}
	buf[x] = ff_vorbis_floor1_inverse_db_table[av_clip_uint8(y)];
	}
	}
	}

	void ff_vorbis_floor1_render_list(vorbis_floor1_entry * list, int values,
	uint16_t y_list, int flag,
	int multiplier, float *out, int samples)
	{
	int lx, ly, i;
	lx = 0;
	ly = y_list[0] * multiplier;
	for (i = 1; i < values; i++) {
	int pos = list[i].sort;
	if (flag[pos]) {
	int x1 = list[pos].x;
	int y1 = y_list[pos] * multiplier;
	if (lx < samples)
	render_line(lx, ly, FFMIN(x1,samples), y1, out);
	lx = x1;
	ly = y1;
	}
	if (lx >= samples)
	break;
	}
	if (lx < samples)
	render_line(lx, ly, samples, ly, out);
	}