moov.c

来自「这个库实现了录象功能」· C语言 代码 · 共 320 行

/*******************************************************************************
 moov.c

 libquicktime - A library for reading and writing quicktime/avi/mp4 files.
 http://libquicktime.sourceforge.net

 Copyright (C) 2002 Heroine Virtual Ltd.
 Copyright (C) 2002-2007 Members of the libquicktime project.

 This library 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.

 This library 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 this library; if not, write to the Free Software Foundation, Inc., 51
 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*******************************************************************************/ 

#include "lqt_private.h"
#include <zlib.h>
#include <stdlib.h>
#include <string.h>

#define LOG_DOMAIN "moov"

int quicktime_moov_init(quicktime_moov_t *moov)
{
	int i;

	moov->total_tracks = 0;
	for(i = 0 ; i < MAXTRACKS; i++) moov->trak[i] = 0;
	quicktime_mvhd_init(&(moov->mvhd));
	quicktime_udta_init(&(moov->udta));
	quicktime_ctab_init(&(moov->ctab));
	quicktime_iods_init(&(moov->iods));
	return 0;
}

int quicktime_moov_delete(quicktime_moov_t *moov)
{
	while(moov->total_tracks) quicktime_delete_trak(moov);
	quicktime_mvhd_delete(&(moov->mvhd));
	quicktime_udta_delete(&(moov->udta));
	quicktime_ctab_delete(&(moov->ctab));
	quicktime_iods_delete(&(moov->iods));
	return 0;
}

void quicktime_moov_dump(quicktime_moov_t *moov)
{
	int i;
	lqt_dump("movie (moov)\n");
	quicktime_mvhd_dump(&(moov->mvhd));
	quicktime_udta_dump(&(moov->udta));
        if(moov->has_iods)
          quicktime_iods_dump(&(moov->iods));
        for(i = 0; i < moov->total_tracks; i++)
		quicktime_trak_dump(moov->trak[i]);
        if(moov->has_ctab)
          quicktime_ctab_dump(&(moov->ctab));
        
}

static void* zalloc(void *opaque, unsigned int items, unsigned int size)
{
        return calloc(items, size);
}

static void zfree(void *opaque, void *ptr)
{
        free(ptr);
}

static int read_cmov(quicktime_t *file,
        quicktime_atom_t *parent_atom,
        quicktime_atom_t *moov_atom)
{
        int64_t old_preload_size;
        uint8_t *old_preload_buffer;
        int64_t old_preload_start;
        int64_t old_preload_end;
        int64_t old_preload_ptr;

        quicktime_atom_t leaf_atom;
        unsigned char *data_in, *data_out;
        z_stream zlib;

        do
        {
                quicktime_atom_read_header(file, &leaf_atom);

/* Algorithm used to compress */
                if(quicktime_atom_is(&leaf_atom, "dcom"))
                {
                        char data[5];
                        quicktime_read_data(file, (uint8_t*)data, 4);
                        data[4] = 0;
                        if(strcmp(data, "zlib"))
                        {
                                lqt_log(NULL, LQT_LOG_ERROR, LOG_DOMAIN,
                                        "read_cmov: compression '%c%c%c%c' not zlib.",
                                        data[0],
                                        data[1],
                                        data[2],
                                        data[3]);
                                return 1;
                        }

                        quicktime_atom_skip(file, &leaf_atom);
                }
                else
/* Size of uncompressed data followed by compressed data */
                if(quicktime_atom_is(&leaf_atom, "cmvd"))
                {
/* Size of uncompressed data */
                        int uncompressed_size = quicktime_read_int32(file);
/* Read compressed data */
                        int compressed_size = leaf_atom.end - quicktime_position(file);

                        data_in = calloc(1, compressed_size);
                        quicktime_read_data(file, data_in, compressed_size);
/* Decompress to another buffer */
                        data_out = calloc(1, uncompressed_size + 0x400);
                        zlib.zalloc = zalloc;
                        zlib.zfree = zfree;
                        zlib.opaque = NULL;
                        zlib.avail_out = uncompressed_size + 0x400;
                        zlib.next_out = data_out;
                        zlib.avail_in = compressed_size;
                        zlib.next_in = data_in;
                        inflateInit(&zlib);
                        inflate(&zlib, Z_PARTIAL_FLUSH);
                        inflateEnd(&zlib);
                        free(data_in);
                        file->moov_data = data_out;

/*
 * FILE *test = fopen("/tmp/test", "w");
 * fwrite(data_out, uncompressed_size, 1, test);
 * fclose(test);
 * exit(0);
 */


/* Trick library into reading temporary buffer for the moov */
                        file->moov_end = moov_atom->end;
                        file->moov_size = moov_atom->size;
                        moov_atom->end = moov_atom->start + uncompressed_size;
                        moov_atom->size = uncompressed_size;
                        old_preload_size = file->preload_size;
                        old_preload_buffer = file->preload_buffer;
                        old_preload_start = file->preload_start;
                        old_preload_end = file->preload_end;
                        old_preload_ptr = file->preload_ptr;
                        file->preload_size = uncompressed_size;
                        file->preload_buffer = data_out;
                        file->preload_start = moov_atom->start;
                        file->preload_end = file->preload_start + uncompressed_size;
                        file->preload_ptr = 0;
                        quicktime_set_position(file, file->preload_start + 8);
/* Try again */
                        if(quicktime_read_moov(file,
                                &file->moov,
                                moov_atom))
                                return 1;
/* Exit the compressed state */
                        moov_atom->size = file->moov_size;
                        moov_atom->end = file->moov_end;
                        file->preload_size = old_preload_size;
                        file->preload_buffer = old_preload_buffer;
                        file->preload_start = old_preload_start;
                        file->preload_end = old_preload_end;
                        file->preload_ptr = old_preload_ptr;
                        quicktime_set_position(file, moov_atom->end);
                }
                else
                        quicktime_atom_skip(file, &leaf_atom);
        }while(quicktime_position(file) < parent_atom->end);
        return 0;
}


int quicktime_read_moov(quicktime_t *file, quicktime_moov_t *moov, quicktime_atom_t *parent_atom)
{
/* mandatory mvhd */
	quicktime_atom_t leaf_atom;

/* AVI translation: */
/* strh -> mvhd */

        do
        {
                quicktime_atom_read_header(file, &leaf_atom);

                if(quicktime_atom_is(&leaf_atom, "cmov"))
                {
                        file->compressed_moov = 1;
                        if(read_cmov(file, &leaf_atom, parent_atom)) return 1;
/* Now were reading the compressed moov atom from the beginning. */
                }
                else
		if(quicktime_atom_is(&leaf_atom, "mvhd"))
		{
                        quicktime_read_mvhd(file, &(moov->mvhd), &leaf_atom);
		}
		else
		if(quicktime_atom_is(&leaf_atom, "clip"))
		{
			quicktime_atom_skip(file, &leaf_atom);
		}
		else
		if(quicktime_atom_is(&leaf_atom, "trak"))
		{
			quicktime_trak_t *trak = quicktime_add_trak(file);
			quicktime_read_trak(file, trak, &leaf_atom);
		}
		else
		if(quicktime_atom_is(&leaf_atom, "udta"))
		{
			quicktime_read_udta(file, &(moov->udta), &leaf_atom);
			quicktime_atom_skip(file, &leaf_atom);
		}
		else
		if(quicktime_atom_is(&leaf_atom, "ctab"))
		{
                quicktime_read_ctab(file, &(moov->ctab));
                moov->has_ctab = 1;
                }
		else
		if(quicktime_atom_is(&leaf_atom, "iods"))
		{
                        quicktime_read_iods(file, &(moov->iods));
			quicktime_atom_skip(file, &leaf_atom);
                        moov->has_iods = 1;
		}
		else
		quicktime_atom_skip(file, &leaf_atom);
	}while(quicktime_position(file) < parent_atom->end);
	
	return 0;
}

void quicktime_finalize_moov(quicktime_t *file, quicktime_moov_t *moov)
  {
  int i;
  int64_t longest_duration = 0;
  int64_t duration;
  int timescale;
  /* get the duration from the longest track in the mvhd's timescale */
  for(i = 0; i < moov->total_tracks; i++)
    {
    quicktime_trak_fix_counts(file, moov->trak[i], moov->mvhd.time_scale);
    quicktime_trak_duration(moov->trak[i], &duration, &timescale);
    
    duration = (long)((float)duration / timescale * moov->mvhd.time_scale);
    
    if(duration > longest_duration)
      {
      longest_duration = duration;
      }
    
    /* Add tracks to iods */
    quicktime_iods_add_track(&(moov->iods), moov->trak[i]);
    }
  moov->mvhd.duration = longest_duration;
  if(!IS_MP4(file->file_type))
    moov->mvhd.selection_duration = longest_duration;
  }

void quicktime_write_moov(quicktime_t *file, quicktime_moov_t *moov)
{
	quicktime_atom_t atom;
	int result, i;


// Try moov header immediately
	file->mdat.atom.end = quicktime_position(file);
	result = quicktime_atom_write_header(file, &atom, "moov");

// Disk full.  Rewind and try again
	if(result)
	{
		quicktime_set_position(file, file->mdat.atom.end - (int64_t)0x100000);
		file->mdat.atom.end = quicktime_position(file);
		quicktime_atom_write_header(file, &atom, "moov");
	}
        quicktime_write_mvhd(file, &(moov->mvhd));
        if(moov->has_iods)
          quicktime_write_iods(file, moov);
	for(i = 0; i < moov->total_tracks; i++)
          {
          quicktime_write_trak(file, moov->trak[i]);
          }
	quicktime_write_udta(file, &(moov->udta));
	/*quicktime_write_ctab(file, &(moov->ctab)); */

	quicktime_atom_write_footer(file, &atom);
}

void quicktime_update_durations(quicktime_moov_t *moov)
{
	
}

int quicktime_shift_offsets(quicktime_moov_t *moov, int64_t offset)
{
	int i;
	for(i = 0; i < moov->total_tracks; i++)
	{
		quicktime_trak_shift_offsets(moov->trak[i], offset);
	}
	return 0;
}