tools/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  * To compile this program, start from the base directory from which you
  11  * are building FFmpeg and type:
  12  *  make tools/qt-faststart
  13  * The qt-faststart program will be built in the tools/ directory. If you
  14  * do not build the program in this manner, correct results are not
  15  * guaranteed, particularly on 64-bit platforms.
  16  * Invoke the program with:
  17  *  qt-faststart <infile.mov> <outfile.mov>
  18  *
  19  * Notes: Quicktime files can come in many configurations of top-level
  20  * atoms. This utility stipulates that the very last atom in the file needs
  21  * to be a moov atom. When given such a file, this utility will rearrange
  22  * the top-level atoms by shifting the moov atom from the back of the file
  23  * to the front, and patch the chunk offsets along the way. This utility
  24  * presently only operates on uncompressed moov atoms.
  25  */
  26
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <inttypes.h>
  30
  31 #ifdef __MINGW32__
  32 #define fseeko(x,y,z)  fseeko64(x,y,z)
  33 #define ftello(x)      ftello64(x)
  34 #endif
  35
  36 #define BE_16(x) ((((uint8_t*)(x))[0] << 8) | ((uint8_t*)(x))[1])
  37 #define BE_32(x) ((((uint8_t*)(x))[0] << 24) | \
  38                   (((uint8_t*)(x))[1] << 16) | \
  39                   (((uint8_t*)(x))[2] << 8) | \
  40                    ((uint8_t*)(x))[3])
  41 #define BE_64(x) (((uint64_t)(((uint8_t*)(x))[0]) << 56) | \
  42                   ((uint64_t)(((uint8_t*)(x))[1]) << 48) | \
  43                   ((uint64_t)(((uint8_t*)(x))[2]) << 40) | \
  44                   ((uint64_t)(((uint8_t*)(x))[3]) << 32) | \
  45                   ((uint64_t)(((uint8_t*)(x))[4]) << 24) | \
  46                   ((uint64_t)(((uint8_t*)(x))[5]) << 16) | \
  47                   ((uint64_t)(((uint8_t*)(x))[6]) << 8) | \
  48                   ((uint64_t)((uint8_t*)(x))[7]))
  49
  50 #define BE_FOURCC( ch0, ch1, ch2, ch3 )             \
  51         ( (uint32_t)(unsigned char)(ch3) |          \
  52         ( (uint32_t)(unsigned char)(ch2) << 8 ) |   \
  53         ( (uint32_t)(unsigned char)(ch1) << 16 ) |  \
  54         ( (uint32_t)(unsigned char)(ch0) << 24 ) )
  55
  56 #define QT_ATOM BE_FOURCC
  57 /* top level atoms */
  58 #define FREE_ATOM QT_ATOM('f', 'r', 'e', 'e')
  59 #define JUNK_ATOM QT_ATOM('j', 'u', 'n', 'k')
  60 #define MDAT_ATOM QT_ATOM('m', 'd', 'a', 't')
  61 #define MOOV_ATOM QT_ATOM('m', 'o', 'o', 'v')
  62 #define PNOT_ATOM QT_ATOM('p', 'n', 'o', 't')
  63 #define SKIP_ATOM QT_ATOM('s', 'k', 'i', 'p')
  64 #define WIDE_ATOM QT_ATOM('w', 'i', 'd', 'e')
  65 #define PICT_ATOM QT_ATOM('P', 'I', 'C', 'T')
  66 #define FTYP_ATOM QT_ATOM('f', 't', 'y', 'p')
  67
  68 #define CMOV_ATOM QT_ATOM('c', 'm', 'o', 'v')
  69 #define STCO_ATOM QT_ATOM('s', 't', 'c', 'o')
  70 #define CO64_ATOM QT_ATOM('c', 'o', '6', '4')
  71
  72 #define ATOM_PREAMBLE_SIZE 8
  73 #define COPY_BUFFER_SIZE 1024
  74
  75 int main(int argc, char *argv[])
  76 {
  77     FILE *infile;
  78     FILE *outfile;
  79     unsigned char atom_bytes[ATOM_PREAMBLE_SIZE];
  80     uint32_t atom_type = 0;
  81     uint64_t atom_size = 0;
  82     uint64_t last_offset;
  83     unsigned char *moov_atom;
  84     unsigned char *ftyp_atom = 0;
  85     uint64_t moov_atom_size;
  86     uint64_t ftyp_atom_size = 0;
  87     uint64_t i, j;
  88     uint32_t offset_count;
  89     uint64_t current_offset;
  90     uint64_t start_offset = 0;
  91     unsigned char copy_buffer[COPY_BUFFER_SIZE];
  92     int bytes_to_copy;
  93
  94     if (argc != 3) {
  95         printf ("Usage: qt-faststart <infile.mov> <outfile.mov>\n");
  96         return 0;
  97     }
  98
  99     infile = fopen(argv[1], "rb");
 100     if (!infile) {
 101         perror(argv[1]);
 102         return 1;
 103     }
 104
 105     /* traverse through the atoms in the file to make sure that 'moov' is
 106      * at the end */
 107     while (!feof(infile)) {
 108         if (fread(atom_bytes, ATOM_PREAMBLE_SIZE, 1, infile) != 1) {
 109             break;
 110         }
 111         atom_size = (uint32_t)BE_32(&atom_bytes[0]);
 112         atom_type = BE_32(&atom_bytes[4]);
 113
 114         if ((atom_type != FREE_ATOM) &&
 115             (atom_type != JUNK_ATOM) &&
 116             (atom_type != MDAT_ATOM) &&
 117             (atom_type != MOOV_ATOM) &&
 118             (atom_type != PNOT_ATOM) &&
 119             (atom_type != SKIP_ATOM) &&
 120             (atom_type != WIDE_ATOM) &&
 121             (atom_type != PICT_ATOM) &&
 122             (atom_type != FTYP_ATOM)) {
 123             printf ("encountered non-QT top-level atom (is this a Quicktime file?)\n");
 124             break;
 125         }
 126
 127         /* keep ftyp atom */
 128         if (atom_type == FTYP_ATOM) {
 129             ftyp_atom_size = atom_size;
 130             ftyp_atom = malloc(ftyp_atom_size);
 131             if (!ftyp_atom) {
 132                 printf ("could not allocate 0x%llX byte for ftyp atom\n",
 133                         atom_size);
 134                 fclose(infile);
 135                 return 1;
 136             }
 137             fseeko(infile, -ATOM_PREAMBLE_SIZE, SEEK_CUR);
 138             if (fread(ftyp_atom, atom_size, 1, infile) != 1) {
 139                 perror(argv[1]);
 140                 free(ftyp_atom);
 141                 fclose(infile);
 142                 return 1;
 143             }
 144             start_offset = ftello(infile);
 145             continue;
 146         }
 147
 148         /* 64-bit special case */
 149         if (atom_size == 1) {
 150             if (fread(atom_bytes, ATOM_PREAMBLE_SIZE, 1, infile) != 1) {
 151                 break;
 152             }
 153             atom_size = BE_64(&atom_bytes[0]);
 154             fseeko(infile, atom_size - ATOM_PREAMBLE_SIZE * 2, SEEK_CUR);
 155         } else {
 156             fseeko(infile, atom_size - ATOM_PREAMBLE_SIZE, SEEK_CUR);
 157         }
 158     }
 159
 160     if (atom_type != MOOV_ATOM) {
 161         printf ("last atom in file was not a moov atom\n");
 162         fclose(infile);
 163         return 0;
 164     }
 165
 166     /* moov atom was, in fact, the last atom in the chunk; load the whole
 167      * moov atom */
 168     fseeko(infile, -atom_size, SEEK_END);
 169     last_offset = ftello(infile);
 170     moov_atom_size = atom_size;
 171     moov_atom = malloc(moov_atom_size);
 172     if (!moov_atom) {
 173         printf ("could not allocate 0x%llX byte for moov atom\n",
 174             atom_size);
 175         fclose(infile);
 176         return 1;
 177     }
 178     if (fread(moov_atom, atom_size, 1, infile) != 1) {
 179         perror(argv[1]);
 180         free(moov_atom);
 181         fclose(infile);
 182         return 1;
 183     }
 184
 185     /* this utility does not support compressed atoms yet, so disqualify
 186      * files with compressed QT atoms */
 187     if (BE_32(&moov_atom[12]) == CMOV_ATOM) {
 188         printf ("this utility does not support compressed moov atoms yet\n");
 189         free(moov_atom);
 190         fclose(infile);
 191         return 1;
 192     }
 193
 194     /* close; will be re-opened later */
 195     fclose(infile);
 196
 197     /* crawl through the moov chunk in search of stco or co64 atoms */
 198     for (i = 4; i < moov_atom_size - 4; i++) {
 199         atom_type = BE_32(&moov_atom[i]);
 200         if (atom_type == STCO_ATOM) {
 201             printf (" patching stco atom...\n");
 202             atom_size = BE_32(&moov_atom[i - 4]);
 203             if (i + atom_size - 4 > moov_atom_size) {
 204                 printf (" bad atom size\n");
 205                 free(moov_atom);
 206                 return 1;
 207             }
 208             offset_count = BE_32(&moov_atom[i + 8]);
 209             for (j = 0; j < offset_count; j++) {
 210                 current_offset = BE_32(&moov_atom[i + 12 + j * 4]);
 211                 current_offset += moov_atom_size;
 212                 moov_atom[i + 12 + j * 4 + 0] = (current_offset >> 24) & 0xFF;
 213                 moov_atom[i + 12 + j * 4 + 1] = (current_offset >> 16) & 0xFF;
 214                 moov_atom[i + 12 + j * 4 + 2] = (current_offset >>  8) & 0xFF;
 215                 moov_atom[i + 12 + j * 4 + 3] = (current_offset >>  0) & 0xFF;
 216             }
 217             i += atom_size - 4;
 218         } else if (atom_type == CO64_ATOM) {
 219             printf (" patching co64 atom...\n");
 220             atom_size = BE_32(&moov_atom[i - 4]);
 221             if (i + atom_size - 4 > moov_atom_size) {
 222                 printf (" bad atom size\n");
 223                 free(moov_atom);
 224                 return 1;
 225             }
 226             offset_count = BE_32(&moov_atom[i + 8]);
 227             for (j = 0; j < offset_count; j++) {
 228                 current_offset = BE_64(&moov_atom[i + 12 + j * 8]);
 229                 current_offset += moov_atom_size;
 230                 moov_atom[i + 12 + j * 8 + 0] = (current_offset >> 56) & 0xFF;
 231                 moov_atom[i + 12 + j * 8 + 1] = (current_offset >> 48) & 0xFF;
 232                 moov_atom[i + 12 + j * 8 + 2] = (current_offset >> 40) & 0xFF;
 233                 moov_atom[i + 12 + j * 8 + 3] = (current_offset >> 32) & 0xFF;
 234                 moov_atom[i + 12 + j * 8 + 4] = (current_offset >> 24) & 0xFF;
 235                 moov_atom[i + 12 + j * 8 + 5] = (current_offset >> 16) & 0xFF;
 236                 moov_atom[i + 12 + j * 8 + 6] = (current_offset >>  8) & 0xFF;
 237                 moov_atom[i + 12 + j * 8 + 7] = (current_offset >>  0) & 0xFF;
 238             }
 239             i += atom_size - 4;
 240         }
 241     }
 242
 243     /* re-open the input file and open the output file */
 244     infile = fopen(argv[1], "rb");
 245     if (!infile) {
 246         perror(argv[1]);
 247         free(moov_atom);
 248         return 1;
 249     }
 250
 251     if (start_offset > 0) { /* seek after ftyp atom */
 252         fseeko(infile, start_offset, SEEK_SET);
 253         last_offset -= start_offset;
 254     }
 255
 256     outfile = fopen(argv[2], "wb");
 257     if (!outfile) {
 258         perror(argv[2]);
 259         fclose(outfile);
 260         free(moov_atom);
 261         return 1;
 262     }
 263
 264     /* dump the same ftyp atom */
 265     if (ftyp_atom_size > 0) {
 266         printf (" writing ftyp atom...\n");
 267         if (fwrite(ftyp_atom, ftyp_atom_size, 1, outfile) != 1) {
 268             perror(argv[2]);
 269             goto error_out;
 270         }
 271     }
 272
 273     /* dump the new moov atom */
 274     printf (" writing moov atom...\n");
 275     if (fwrite(moov_atom, moov_atom_size, 1, outfile) != 1) {
 276         perror(argv[2]);
 277         goto error_out;
 278     }
 279
 280     /* copy the remainder of the infile, from offset 0 -> last_offset - 1 */
 281     printf (" copying rest of file...\n");
 282     while (last_offset) {
 283         if (last_offset > COPY_BUFFER_SIZE)
 284             bytes_to_copy = COPY_BUFFER_SIZE;
 285         else
 286             bytes_to_copy = last_offset;
 287
 288         if (fread(copy_buffer, bytes_to_copy, 1, infile) != 1) {
 289             perror(argv[1]);
 290             goto error_out;
 291         }
 292         if (fwrite(copy_buffer, bytes_to_copy, 1, outfile) != 1) {
 293             perror(argv[2]);
 294             goto error_out;
 295         }
 296
 297         last_offset -= bytes_to_copy;
 298     }
 299
 300     fclose(infile);
 301     fclose(outfile);
 302     free(moov_atom);
 303     if (ftyp_atom_size > 0)
 304         free(ftyp_atom);
 305
 306     return 0;
 307
 308 error_out:
 309     fclose(infile);
 310     fclose(outfile);
 311     free(moov_atom);
 312     if (ftyp_atom_size > 0)
 313         free(ftyp_atom);
 314     return 1;
 315 }