qt-faststart.c

   1 /*
   2  * qt-faststart.c, v0.1
   3  * by Mike Melanson (melanson@pcisys.net)
   4  * This file is placed in the public domain. Use the program however you
   5  * see fit.
   6  *
   7  * This utility rearranges a Quicktime file such that the moov atom
   8  * is in front of the data, thus facilitating network streaming.
   9  *
  10  * Compile this program using:
  11  *  make qt-faststart
  12  * Invoke the program with:
  13  *  qt-faststart <infile.mov> <outfile.mov>
  14  *
  15  * Notes: Quicktime files can come in many configurations of top-level
  16  * atoms. This utility stipulates that the very last atom in the file needs
  17  * to be a moov atom. When given such a file, this utility will rearrange
  18  * the top-level atoms by shifting the moov atom from the back of the file
  19  * to the front, and patch the chunk offsets along the way. This utility
  20  * presently only operates on uncompressed moov atoms.
  21  */
  22
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <inttypes.h>
  26
  27 #ifdef __MINGW32__
  28 #define fseeko(x,y,z)  fseeko64(x,y,z)
  29 #define ftello(x)      ftello64(x)
  30 #endif
  31
  32 #define BE_16(x) ((((uint8_t*)(x))[0] << 8) | ((uint8_t*)(x))[1])
  33 #define BE_32(x) ((((uint8_t*)(x))[0] << 24) | \
  34                   (((uint8_t*)(x))[1] << 16) | \
  35                   (((uint8_t*)(x))[2] << 8) | \
  36                    ((uint8_t*)(x))[3])
  37 #define BE_64(x) (((uint64_t)(((uint8_t*)(x))[0]) << 56) | \
  38                   ((uint64_t)(((uint8_t*)(x))[1]) << 48) | \
  39                   ((uint64_t)(((uint8_t*)(x))[2]) << 40) | \
  40                   ((uint64_t)(((uint8_t*)(x))[3]) << 32) | \
  41                   ((uint64_t)(((uint8_t*)(x))[4]) << 24) | \
  42                   ((uint64_t)(((uint8_t*)(x))[5]) << 16) | \
  43                   ((uint64_t)(((uint8_t*)(x))[6]) << 8) | \
  44                   ((uint64_t)((uint8_t*)(x))[7]))
  45
  46 #define BE_FOURCC( ch0, ch1, ch2, ch3 )             \
  47         ( (uint32_t)(unsigned char)(ch3) |          \
  48         ( (uint32_t)(unsigned char)(ch2) << 8 ) |   \
  49         ( (uint32_t)(unsigned char)(ch1) << 16 ) |  \
  50         ( (uint32_t)(unsigned char)(ch0) << 24 ) )
  51
  52 #define QT_ATOM BE_FOURCC
  53 /* top level atoms */
  54 #define FREE_ATOM QT_ATOM('f', 'r', 'e', 'e')
  55 #define JUNK_ATOM QT_ATOM('j', 'u', 'n', 'k')
  56 #define MDAT_ATOM QT_ATOM('m', 'd', 'a', 't')
  57 #define MOOV_ATOM QT_ATOM('m', 'o', 'o', 'v')
  58 #define PNOT_ATOM QT_ATOM('p', 'n', 'o', 't')
  59 #define SKIP_ATOM QT_ATOM('s', 'k', 'i', 'p')
  60 #define WIDE_ATOM QT_ATOM('w', 'i', 'd', 'e')
  61 #define PICT_ATOM QT_ATOM('P', 'I', 'C', 'T')
  62 #define FTYP_ATOM QT_ATOM('f', 't', 'y', 'p')
  63
  64 #define CMOV_ATOM QT_ATOM('c', 'm', 'o', 'v')
  65 #define STCO_ATOM QT_ATOM('s', 't', 'c', 'o')
  66 #define CO64_ATOM QT_ATOM('c', 'o', '6', '4')
  67
  68 #define ATOM_PREAMBLE_SIZE 8
  69 #define COPY_BUFFER_SIZE 1024
  70
  71 int main(int argc, char *argv[])
  72 {
  73     FILE *infile;
  74     FILE *outfile;
  75     unsigned char atom_bytes[ATOM_PREAMBLE_SIZE];
  76     uint32_t atom_type = 0;
  77     uint64_t atom_size = 0;
  78     uint64_t last_offset;
  79     unsigned char *moov_atom;
  80     unsigned char *ftyp_atom = 0;
  81     uint64_t moov_atom_size;
  82     uint64_t ftyp_atom_size = 0;
  83     uint64_t i, j;
  84     uint32_t offset_count;
  85     uint64_t current_offset;
  86     uint64_t start_offset = 0;
  87     unsigned char copy_buffer[COPY_BUFFER_SIZE];
  88     int bytes_to_copy;
  89
  90     if (argc != 3) {
  91         printf ("Usage: qt-faststart <infile.mov> <outfile.mov>\n");
  92         return 0;
  93     }
  94
  95     infile = fopen(argv[1], "rb");
  96     if (!infile) {
  97         perror(argv[1]);
  98         return 1;
  99     }
 100
 101     /* traverse through the atoms in the file to make sure that 'moov' is
 102      * at the end */
 103     while (!feof(infile)) {
 104         if (fread(atom_bytes, ATOM_PREAMBLE_SIZE, 1, infile) != 1) {
 105             break;
 106         }
 107         atom_size = (uint32_t)BE_32(&atom_bytes[0]);
 108         atom_type = BE_32(&atom_bytes[4]);
 109
 110         if ((atom_type != FREE_ATOM) &&
 111             (atom_type != JUNK_ATOM) &&
 112             (atom_type != MDAT_ATOM) &&
 113             (atom_type != MOOV_ATOM) &&
 114             (atom_type != PNOT_ATOM) &&
 115             (atom_type != SKIP_ATOM) &&
 116             (atom_type != WIDE_ATOM) &&
 117             (atom_type != PICT_ATOM) &&
 118             (atom_type != FTYP_ATOM)) {
 119             printf ("encountered non-QT top-level atom (is this a Quicktime file?)\n");
 120             break;
 121         }
 122
 123         /* keep ftyp atom */
 124         if (atom_type == FTYP_ATOM) {
 125             ftyp_atom_size = atom_size;
 126             ftyp_atom = malloc(ftyp_atom_size);
 127             if (!ftyp_atom) {
 128                 printf ("could not allocate 0x%llX byte for ftyp atom\n",
 129                         atom_size);
 130                 fclose(infile);
 131                 return 1;
 132             }
 133             fseeko(infile, -ATOM_PREAMBLE_SIZE, SEEK_CUR);
 134             if (fread(ftyp_atom, atom_size, 1, infile) != 1) {
 135                 perror(argv[1]);
 136                 free(ftyp_atom);
 137                 fclose(infile);
 138                 return 1;
 139             }
 140             start_offset = ftello(infile);
 141             continue;
 142         }
 143
 144         /* 64-bit special case */
 145         if (atom_size == 1) {
 146             if (fread(atom_bytes, ATOM_PREAMBLE_SIZE, 1, infile) != 1) {
 147                 break;
 148             }
 149             atom_size = BE_64(&atom_bytes[0]);
 150             fseeko(infile, atom_size - ATOM_PREAMBLE_SIZE * 2, SEEK_CUR);
 151         } else {
 152             fseeko(infile, atom_size - ATOM_PREAMBLE_SIZE, SEEK_CUR);
 153         }
 154     }
 155
 156     if (atom_type != MOOV_ATOM) {
 157         printf ("last atom in file was not a moov atom\n");
 158         fclose(infile);
 159         return 0;
 160     }
 161
 162     /* moov atom was, in fact, the last atom in the chunk; load the whole
 163      * moov atom */
 164     fseeko(infile, -atom_size, SEEK_END);
 165     last_offset = ftello(infile);
 166     moov_atom_size = atom_size;
 167     moov_atom = malloc(moov_atom_size);
 168     if (!moov_atom) {
 169         printf ("could not allocate 0x%llX byte for moov atom\n",
 170             atom_size);
 171         fclose(infile);
 172         return 1;
 173     }
 174     if (fread(moov_atom, atom_size, 1, infile) != 1) {
 175         perror(argv[1]);
 176         free(moov_atom);
 177         fclose(infile);
 178         return 1;
 179     }
 180
 181     /* this utility does not support compressed atoms yet, so disqualify
 182      * files with compressed QT atoms */
 183     if (BE_32(&moov_atom[12]) == CMOV_ATOM) {
 184         printf ("this utility does not support compressed moov atoms yet\n");
 185         free(moov_atom);
 186         fclose(infile);
 187         return 1;
 188     }
 189
 190     /* close; will be re-opened later */
 191     fclose(infile);
 192
 193     /* crawl through the moov chunk in search of stco or co64 atoms */
 194     for (i = 4; i < moov_atom_size - 4; i++) {
 195         atom_type = BE_32(&moov_atom[i]);
 196         if (atom_type == STCO_ATOM) {
 197             printf (" patching stco atom...\n");
 198             atom_size = BE_32(&moov_atom[i - 4]);
 199             if (i + atom_size - 4 > moov_atom_size) {
 200                 printf (" bad atom size\n");
 201                 free(moov_atom);
 202                 return 1;
 203             }
 204             offset_count = BE_32(&moov_atom[i + 8]);
 205             for (j = 0; j < offset_count; j++) {
 206                 current_offset = BE_32(&moov_atom[i + 12 + j * 4]);
 207                 current_offset += moov_atom_size;
 208                 moov_atom[i + 12 + j * 4 + 0] = (current_offset >> 24) & 0xFF;
 209                 moov_atom[i + 12 + j * 4 + 1] = (current_offset >> 16) & 0xFF;
 210                 moov_atom[i + 12 + j * 4 + 2] = (current_offset >>  8) & 0xFF;
 211                 moov_atom[i + 12 + j * 4 + 3] = (current_offset >>  0) & 0xFF;
 212             }
 213             i += atom_size - 4;
 214         } else if (atom_type == CO64_ATOM) {
 215             printf (" patching co64 atom...\n");
 216             atom_size = BE_32(&moov_atom[i - 4]);
 217             if (i + atom_size - 4 > moov_atom_size) {
 218                 printf (" bad atom size\n");
 219                 free(moov_atom);
 220                 return 1;
 221             }
 222             offset_count = BE_32(&moov_atom[i + 8]);
 223             for (j = 0; j < offset_count; j++) {
 224                 current_offset = BE_64(&moov_atom[i + 12 + j * 8]);
 225                 current_offset += moov_atom_size;
 226                 moov_atom[i + 12 + j * 8 + 0] = (current_offset >> 56) & 0xFF;
 227                 moov_atom[i + 12 + j * 8 + 1] = (current_offset >> 48) & 0xFF;
 228                 moov_atom[i + 12 + j * 8 + 2] = (current_offset >> 40) & 0xFF;
 229                 moov_atom[i + 12 + j * 8 + 3] = (current_offset >> 32) & 0xFF;
 230                 moov_atom[i + 12 + j * 8 + 4] = (current_offset >> 24) & 0xFF;
 231                 moov_atom[i + 12 + j * 8 + 5] = (current_offset >> 16) & 0xFF;
 232                 moov_atom[i + 12 + j * 8 + 6] = (current_offset >>  8) & 0xFF;
 233                 moov_atom[i + 12 + j * 8 + 7] = (current_offset >>  0) & 0xFF;
 234             }
 235             i += atom_size - 4;
 236         }
 237     }
 238
 239     /* re-open the input file and open the output file */
 240     infile = fopen(argv[1], "rb");
 241     if (!infile) {
 242         perror(argv[1]);
 243         free(moov_atom);
 244         return 1;
 245     }
 246
 247     if (start_offset > 0) { /* seek after ftyp atom */
 248         fseeko(infile, start_offset, SEEK_SET);
 249         last_offset -= start_offset;
 250     }
 251
 252     outfile = fopen(argv[2], "wb");
 253     if (!outfile) {
 254         perror(argv[2]);
 255         fclose(outfile);
 256         free(moov_atom);
 257         return 1;
 258     }
 259
 260     /* dump the same ftyp atom */
 261     if (ftyp_atom_size > 0) {
 262         printf (" writing ftyp atom...\n");
 263         if (fwrite(ftyp_atom, ftyp_atom_size, 1, outfile) != 1) {
 264             perror(argv[2]);
 265             goto error_out;
 266         }
 267     }
 268
 269     /* dump the new moov atom */
 270     printf (" writing moov atom...\n");
 271     if (fwrite(moov_atom, moov_atom_size, 1, outfile) != 1) {
 272         perror(argv[2]);
 273         goto error_out;
 274     }
 275
 276     /* copy the remainder of the infile, from offset 0 -> last_offset - 1 */
 277     printf (" copying rest of file...\n");
 278     while (last_offset) {
 279         if (last_offset > COPY_BUFFER_SIZE)
 280             bytes_to_copy = COPY_BUFFER_SIZE;
 281         else
 282             bytes_to_copy = last_offset;
 283
 284         if (fread(copy_buffer, bytes_to_copy, 1, infile) != 1) {
 285             perror(argv[1]);
 286             goto error_out;
 287         }
 288         if (fwrite(copy_buffer, bytes_to_copy, 1, outfile) != 1) {
 289             perror(argv[2]);
 290             goto error_out;
 291         }
 292
 293         last_offset -= bytes_to_copy;
 294     }
 295
 296     fclose(infile);
 297     fclose(outfile);
 298     free(moov_atom);
 299     if (ftyp_atom_size > 0)
 300         free(ftyp_atom);
 301
 302     return 0;
 303
 304 error_out:
 305     fclose(infile);
 306     fclose(outfile);
 307     free(moov_atom);
 308     if (ftyp_atom_size > 0)
 309         free(ftyp_atom);
 310     return 1;
 311 }