spudec.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.

/* SPUdec.c
   Skeleton of function spudec_process_controll() is from xine sources.
   Further works:
   LGB,... (yeah, try to improve it and insert your name here! ;-)

   Kim Minh Kaplan
   implement fragments reassembly, RLE decoding.
   read brightness from the IFO.

   For information on SPU format see <URL:http://sam.zoy.org/doc/dvd/subtitles/>
   and <URL:http://members.aol.com/mpucoder/DVD/spu.html>

 */
#include "config.h"
#include "mp_msg.h"

#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <math.h>
#include "libvo/video_out.h"
#include "spudec.h"
//#include "postproc/swscale.h"

#define MIN(a, b)	((a)<(b)?(a):(b))

/* Valid values for spu_aamode:
   0: none (fastest, most ugly)
   1: approximate
   2: full (slowest)
   3: bilinear (similiar to vobsub, fast and not too bad)
   4: uses swscaler gaussian (this is the only one that looks good)
 */

int spu_aamode = 3;
int spu_alignment = -1;
float spu_gaussvar = 1.0;
extern int sub_pos;

typedef struct packet_t packet_t;
struct packet_t {
  unsigned char *packet;
  unsigned int palette[4];
  unsigned int alpha[4];
  unsigned int control_start;	/* index of start of control data */
  unsigned int current_nibble[2]; /* next data nibble (4 bits) to be
                                     processed (for RLE decoding) for
                                     even and odd lines */
  int deinterlace_oddness;	/* 0 or 1, index into current_nibble */
  unsigned int start_col, end_col;
  unsigned int start_row, end_row;
  unsigned int width, height, stride;
  unsigned int start_pts, end_pts;
  packet_t *next;
};

typedef struct {
  packet_t *queue_head;
  packet_t *queue_tail;
  unsigned int global_palette[16];
  unsigned int orig_frame_width, orig_frame_height;
  unsigned char* packet;
  size_t packet_reserve;	/* size of the memory pointed to by packet */
  unsigned int packet_offset;	/* end of the currently assembled fragment */
  unsigned int packet_size;	/* size of the packet once all fragments are assembled */
  unsigned int packet_pts;	/* PTS for this packet */
  unsigned int palette[4];
  unsigned int alpha[4];
  unsigned int cuspal[4];
  unsigned int custom;
  unsigned int now_pts;
  unsigned int start_pts, end_pts;
  unsigned int start_col, end_col;
  unsigned int start_row, end_row;
  unsigned int width, height, stride;
  size_t image_size;		/* Size of the image buffer */
  unsigned char *image;		/* Grayscale value */
  unsigned char *aimage;	/* Alpha value */
  unsigned int scaled_frame_width, scaled_frame_height;
  unsigned int scaled_start_col, scaled_start_row;
  unsigned int scaled_width, scaled_height, scaled_stride;
  size_t scaled_image_size;
  unsigned char *scaled_image;
  unsigned char *scaled_aimage;
  int auto_palette; /* 1 if we lack a palette and must use an heuristic. */
  int font_start_level;  /* Darkest value used for the computed font */
  vo_functions_t *hw_spu;
  int spu_changed;
  unsigned int forced_subs_only;     /* flag: 0=display all subtitle, !0 display only forced subtitles */
  unsigned int is_forced_sub;         /* true if current subtitle is a forced subtitle */
} spudec_handle_t;

static void spudec_queue_packet(spudec_handle_t *this, packet_t *packet)
{
  if (this->queue_head == NULL)
    this->queue_head = packet;
  else
    this->queue_tail->next = packet;
  this->queue_tail = packet;
}

static packet_t *spudec_dequeue_packet(spudec_handle_t *this)
{
  packet_t *retval = this->queue_head;

  this->queue_head = retval->next;
  if (this->queue_head == NULL)
    this->queue_tail = NULL;

  return retval;
}

static void spudec_free_packet(packet_t *packet)
{
  if (packet->packet != NULL)
    free(packet->packet);
  free(packet);
}

static inline unsigned int get_be16(const unsigned char *p)
{
  return (p[0] << 8) + p[1];
}

static inline unsigned int get_be24(const unsigned char *p)
{
  return (get_be16(p) << 8) + p[2];
}

static void next_line(packet_t *packet)
{
  if (packet->current_nibble[packet->deinterlace_oddness] % 2)
    packet->current_nibble[packet->deinterlace_oddness]++;
  packet->deinterlace_oddness = (packet->deinterlace_oddness + 1) % 2;
}

static inline unsigned char get_nibble(packet_t *packet)
{
  unsigned char nib;
  unsigned int *nibblep = packet->current_nibble + packet->deinterlace_oddness;
  if (*nibblep / 2 >= packet->control_start) {
    mp_msg(MSGT_SPUDEC,MSGL_WARN, "SPUdec: ERROR: get_nibble past end of packet\n");
    return 0;
  }
  nib = packet->packet[*nibblep / 2];
  if (*nibblep % 2)
    nib &= 0xf;
  else
    nib >>= 4;
  ++*nibblep;
  return nib;
}

static inline int mkalpha(int i)
{
  /* In mplayer's alpha planes, 0 is transparent, then 1 is nearly
     opaque upto 255 which is transparent */
  switch (i) {
  case 0xf:
    return 1;
  case 0:
    return 0;
  default:
    return (0xf - i) << 4;
  }
}

/* Cut the sub to visible part */
static inline void spudec_cut_image(spudec_handle_t *this)
{
  unsigned int fy, ly;
  unsigned int first_y, last_y;
  unsigned char *image;
  unsigned char *aimage;

  if (this->stride == 0 || this->height == 0) {
    return;
  }

  for (fy = 0; fy < this->image_size && !this->aimage[fy]; fy++);
  for (ly = this->stride * this->height-1; ly && !this->aimage[ly]; ly--);
  first_y = fy / this->stride;
  last_y = ly / this->stride;
  //printf("first_y: %d, last_y: %d\n", first_y, last_y);
  this->start_row += first_y;

  // Some subtitles trigger this condition
  if (last_y + 1 > first_y ) {
	  this->height = last_y - first_y +1;
  } else {
	  this->height = 0;
	  this->image_size = 0;
	  return;
  }
  
//  printf("new h %d new start %d (sz %d st %d)---\n\n", this->height, this->start_row, this->image_size, this->stride);

  image = malloc(2 * this->stride * this->height);
  if(image){
    this->image_size = this->stride * this->height;
    aimage = image + this->image_size;
    memcpy(image, this->image + this->stride * first_y, this->image_size);
    memcpy(aimage, this->aimage + this->stride * first_y, this->image_size);
    free(this->image);
    this->image = image;
    this->aimage = aimage;
  } else {
    mp_msg(MSGT_SPUDEC, MSGL_FATAL, "Fatal: update_spu: malloc requested %d bytes\n", 2 * this->stride * this->height);
  }
}

static void spudec_process_data(spudec_handle_t *this, packet_t *packet)
{
  unsigned int cmap[4], alpha[4];
  unsigned int i, x, y;

  this->scaled_frame_width = 0;
  this->scaled_frame_height = 0;
  this->start_col = packet->start_col;
  this->end_col = packet->end_col;
  this->start_row = packet->start_row;
  this->end_row = packet->end_row;
  this->height = packet->height;
  this->width = packet->width;
  this->stride = packet->stride;
  for (i = 0; i < 4; ++i) {
    alpha[i] = mkalpha(packet->alpha[i]);
    if (alpha[i] == 0)
      cmap[i] = 0;
    else if (this->custom){
      cmap[i] = ((this->cuspal[i] >> 16) & 0xff);
      if (cmap[i] + alpha[i] > 255)
	cmap[i] = 256 - alpha[i];
    }
    else {
      cmap[i] = ((this->global_palette[packet->palette[i]] >> 16) & 0xff);
      if (cmap[i] + alpha[i] > 255)
	cmap[i] = 256 - alpha[i];
    }
  }

  if (this->image_size < this->stride * this->height) {
    if (this->image != NULL) {
      free(this->image);
      this->image_size = 0;
    }
    this->image = malloc(2 * this->stride * this->height);
    if (this->image) {
      this->image_size = this->stride * this->height;
      this->aimage = this->image + this->image_size;
    }
  }
  if (this->image == NULL)
    return;

  /* Kludge: draw_alpha needs width multiple of 8. */
  if (this->width < this->stride)
    for (y = 0; y < this->height; ++y) {
      memset(this->aimage + y * this->stride + this->width, 0, this->stride - this->width);
      /* FIXME: Why is this one needed? */
      memset(this->image + y * this->stride + this->width, 0, this->stride - this->width);
    }

  i = packet->current_nibble[1];
  x = 0;
  y = 0;
  while (packet->current_nibble[0] < i
	 && packet->current_nibble[1] / 2 < packet->control_start
	 && y < this->height) {
    unsigned int len, color;
    unsigned int rle = 0;
    rle = get_nibble(packet);
    if (rle < 0x04) {
      rle = (rle << 4) | get_nibble(packet);
      if (rle < 0x10) {
	rle = (rle << 4) | get_nibble(packet);
	if (rle < 0x040) {
	  rle = (rle << 4) | get_nibble(packet);
	  if (rle < 0x0004)
	    rle |= ((this->width - x) << 2);
	}
      }
    }
    color = 3 - (rle & 0x3);
    len = rle >> 2;
    if (len > this->width - x || len == 0)
      len = this->width - x;
    /* FIXME have to use palette and alpha map*/
    memset(this->image + y * this->stride + x, cmap[color], len);
    memset(this->aimage + y * this->stride + x, alpha[color], len);
    x += len;
    if (x >= this->width) {
      next_line(packet);
      x = 0;
      ++y;
    }
  }
  spudec_cut_image(this);
}


/*
  This function tries to create a usable palette.
  It determines how many non-transparent colors are used, and assigns different
gray scale values to each color.
  I tested it with four streams and even got something readable. Half of the
times I got black characters with white around and half the reverse.
*/
static void compute_palette(spudec_handle_t *this, packet_t *packet)
{
  int used[16],i,cused,start,step,color;

  memset(used, 0, sizeof(used));
  for (i=0; i<4; i++)
    if (packet->alpha[i]) /* !Transparent? */
       used[packet->palette[i]] = 1;
  for (cused=0, i=0; i<16; i++)
    if (used[i]) cused++;
  if (!cused) return;
  if (cused == 1) {
    start = 0x80;
    step = 0;
  } else {
    start = this->font_start_level;
    step = (0xF0-this->font_start_level)/(cused-1);
  }
  memset(used, 0, sizeof(used));
  for (i=0; i<4; i++) {
    color = packet->palette[i];
    if (packet->alpha[i] && !used[color]) { /* not assigned? */
       used[color] = 1;
       this->global_palette[color] = start<<16;
       start += step;
    }
  }
}

static void spudec_process_control(spudec_handle_t *this, unsigned int pts100)
{
  int a,b; /* Temporary vars */
  unsigned int date, type;
  unsigned int off;
  unsigned int start_off = 0;
  unsigned int next_off;
  unsigned int start_pts;
  unsigned int end_pts;
  unsigned int current_nibble[2];
  unsigned int control_start;
  unsigned int display = 0;
  unsigned int start_col = 0;
  unsigned int end_col = 0;
  unsigned int start_row = 0;
  unsigned int end_row = 0;
  unsigned int width = 0;
  unsigned int height = 0;
  unsigned int stride = 0;

  control_start = get_be16(this->packet + 2);
  next_off = control_start;
  while (start_off != next_off) {
    start_off = next_off;
    date = get_be16(this->packet + start_off) * 1024;
    next_off = get_be16(this->packet + start_off + 2);
    mp_msg(MSGT_SPUDEC,MSGL_DBG2, "date=%d\n", date);
    off = start_off + 4;
    for (type = this->packet[off++]; type != 0xff; type = this->packet[off++]) {
      mp_msg(MSGT_SPUDEC,MSGL_DBG2, "cmd=%d  ",type);
      switch(type) {
      case 0x00:
	/* Menu ID, 1 byte */
	mp_msg(MSGT_SPUDEC,MSGL_DBG2,"Menu ID\n");
        /* shouldn't a Menu ID type force display start? */
	start_pts = pts100 + date;
	end_pts = UINT_MAX;
	display = 1;
	this->is_forced_sub=~0; // current subtitle is forced
	break;
      case 0x01:
	/* Start display */
	mp_msg(MSGT_SPUDEC,MSGL_DBG2,"Start display!\n");
	start_pts = pts100 + date;
	end_pts = UINT_MAX;
	display = 1;
	this->is_forced_sub=0;
	break;
      case 0x02:
	/* Stop display */
	mp_msg(MSGT_SPUDEC,MSGL_DBG2,"Stop display!\n");
	end_pts = pts100 + date;
	break;
      case 0x03:
	/* Palette */