/* * qt-faststart.c, v0.2 * by Mike Melanson (melanson@pcisys.net) * This file is placed in the public domain. Use the program however you * see fit. * * This utility rearranges a Quicktime file such that the moov atom * is in front of the data, thus facilitating network streaming. * * To compile this program, start from the base directory from which you * are building FFmpeg and type: * make tools/qt-faststart * The qt-faststart program will be built in the tools/ directory. If you * do not build the program in this manner, correct results are not * guaranteed, particularly on 64-bit platforms. * Invoke the program with: * qt-faststart <infile.mov> <outfile.mov> * * Notes: Quicktime files can come in many configurations of top-level * atoms. This utility stipulates that the very last atom in the file needs * to be a moov atom. When given such a file, this utility will rearrange * the top-level atoms by shifting the moov atom from the back of the file * to the front, and patch the chunk offsets along the way. This utility * presently only operates on uncompressed moov atoms. */ #include <stdio.h> #include <stdlib.h> #include <inttypes.h> #include <string.h> #include <limits.h> #ifdef __MINGW32__ #undef fseeko #define fseeko(x, y, z) fseeko64(x, y, z) #undef ftello #define ftello(x) ftello64(x) #elif defined(_WIN32) #undef fseeko #define fseeko(x, y, z) _fseeki64(x, y, z) #undef ftello #define ftello(x) _ftelli64(x) #endif #define MIN(a,b) ((a) > (b) ? (b) : (a)) #define BE_32(x) (((uint32_t)(((uint8_t*)(x))[0]) << 24) | \ (((uint8_t*)(x))[1] << 16) | \ (((uint8_t*)(x))[2] << 8) | \ ((uint8_t*)(x))[3]) #define BE_64(x) (((uint64_t)(((uint8_t*)(x))[0]) << 56) | \ ((uint64_t)(((uint8_t*)(x))[1]) << 48) | \ ((uint64_t)(((uint8_t*)(x))[2]) << 40) | \ ((uint64_t)(((uint8_t*)(x))[3]) << 32) | \ ((uint64_t)(((uint8_t*)(x))[4]) << 24) | \ ((uint64_t)(((uint8_t*)(x))[5]) << 16) | \ ((uint64_t)(((uint8_t*)(x))[6]) << 8) | \ ((uint64_t)( (uint8_t*)(x))[7])) #define AV_WB32(p, val) { \ ((uint8_t*)(p))[0] = ((val) >> 24) & 0xff; \ ((uint8_t*)(p))[1] = ((val) >> 16) & 0xff; \ ((uint8_t*)(p))[2] = ((val) >> 8) & 0xff; \ ((uint8_t*)(p))[3] = (val) & 0xff; \ } #define AV_WB64(p, val) { \ AV_WB32(p, (val) >> 32) \ AV_WB32(p + 4, val) \ } #define BE_FOURCC(ch0, ch1, ch2, ch3) \ ( (uint32_t)(unsigned char)(ch3) | \ ((uint32_t)(unsigned char)(ch2) << 8) | \ ((uint32_t)(unsigned char)(ch1) << 16) | \ ((uint32_t)(unsigned char)(ch0) << 24) ) #define QT_ATOM BE_FOURCC /* top level atoms */ #define FREE_ATOM QT_ATOM('f', 'r', 'e', 'e') #define JUNK_ATOM QT_ATOM('j', 'u', 'n', 'k') #define MDAT_ATOM QT_ATOM('m', 'd', 'a', 't') #define MOOV_ATOM QT_ATOM('m', 'o', 'o', 'v') #define PNOT_ATOM QT_ATOM('p', 'n', 'o', 't') #define SKIP_ATOM QT_ATOM('s', 'k', 'i', 'p') #define WIDE_ATOM QT_ATOM('w', 'i', 'd', 'e') #define PICT_ATOM QT_ATOM('P', 'I', 'C', 'T') #define FTYP_ATOM QT_ATOM('f', 't', 'y', 'p') #define UUID_ATOM QT_ATOM('u', 'u', 'i', 'd') #define CMOV_ATOM QT_ATOM('c', 'm', 'o', 'v') #define TRAK_ATOM QT_ATOM('t', 'r', 'a', 'k') #define MDIA_ATOM QT_ATOM('m', 'd', 'i', 'a') #define MINF_ATOM QT_ATOM('m', 'i', 'n', 'f') #define STBL_ATOM QT_ATOM('s', 't', 'b', 'l') #define STCO_ATOM QT_ATOM('s', 't', 'c', 'o') #define CO64_ATOM QT_ATOM('c', 'o', '6', '4') #define ATOM_PREAMBLE_SIZE 8 #define COPY_BUFFER_SIZE 33554432 #define MAX_FTYP_ATOM_SIZE 1048576 typedef struct { uint32_t type; uint32_t header_size; uint64_t size; unsigned char *data; } atom_t; typedef struct { uint64_t moov_atom_size; uint64_t stco_offset_count; uint64_t stco_data_size; int stco_overflow; uint32_t depth; } update_chunk_offsets_context_t; typedef struct { unsigned char *dest; uint64_t original_moov_size; uint64_t new_moov_size; } upgrade_stco_context_t; typedef int (*parse_atoms_callback_t)(void *context, atom_t *atom); static int parse_atoms( unsigned char *buf, uint64_t size, parse_atoms_callback_t callback, void *context) { unsigned char *pos = buf; unsigned char *end = pos + size; atom_t atom; int ret; while (end - pos >= ATOM_PREAMBLE_SIZE) { atom.size = BE_32(pos); atom.type = BE_32(pos + 4); pos += ATOM_PREAMBLE_SIZE; atom.header_size = ATOM_PREAMBLE_SIZE; switch (atom.size) { case 1: if (end - pos < 8) { fprintf(stderr, "not enough room for 64 bit atom size\n"); return -1; } atom.size = BE_64(pos); pos += 8; atom.header_size = ATOM_PREAMBLE_SIZE + 8; break; case 0: atom.size = ATOM_PREAMBLE_SIZE + end - pos; break; } if (atom.size < atom.header_size) { fprintf(stderr, "atom size %"PRIu64" too small\n", atom.size); return -1; } atom.size -= atom.header_size; if (atom.size > end - pos) { fprintf(stderr, "atom size %"PRIu64" too big\n", atom.size); return -1; } atom.data = pos; ret = callback(context, &atom); if (ret < 0) { return ret; } pos += atom.size; } return 0; } static int update_stco_offsets(update_chunk_offsets_context_t *context, atom_t *atom) { uint32_t current_offset; uint32_t offset_count; unsigned char *pos; unsigned char *end; printf(" patching stco atom...\n"); if (atom->size < 8) { fprintf(stderr, "stco atom size %"PRIu64" too small\n", atom->size); return -1; } offset_count = BE_32(atom->data + 4); if (offset_count > (atom->size - 8) / 4) { fprintf(stderr, "stco offset count %"PRIu32" too big\n", offset_count); return -1; } context->stco_offset_count += offset_count; context->stco_data_size += atom->size - 8; for (pos = atom->data + 8, end = pos + offset_count * 4; pos < end; pos += 4) { current_offset = BE_32(pos); if (current_offset > UINT_MAX - context->moov_atom_size) { context->stco_overflow = 1; } current_offset += context->moov_atom_size; AV_WB32(pos, current_offset); } return 0; } static int update_co64_offsets(update_chunk_offsets_context_t *context, atom_t *atom) { uint64_t current_offset; uint32_t offset_count; unsigned char *pos; unsigned char *end; printf(" patching co64 atom...\n"); if (atom->size < 8) { fprintf(stderr, "co64 atom size %"PRIu64" too small\n", atom->size); return -1; } offset_count = BE_32(atom->data + 4); if (offset_count > (atom->size - 8) / 8) { fprintf(stderr, "co64 offset count %"PRIu32" too big\n", offset_count); return -1; } for (pos = atom->data + 8, end = pos + offset_count * 8; pos < end; pos += 8) { current_offset = BE_64(pos); current_offset += context->moov_atom_size; AV_WB64(pos, current_offset); } return 0; } static int update_chunk_offsets_callback(void *ctx, atom_t *atom) { update_chunk_offsets_context_t *context = ctx; int ret; switch (atom->type) { case STCO_ATOM: return update_stco_offsets(context, atom); case CO64_ATOM: return update_co64_offsets(context, atom); case MOOV_ATOM: case TRAK_ATOM: case MDIA_ATOM: case MINF_ATOM: case STBL_ATOM: context->depth++; if (context->depth > 10) { fprintf(stderr, "atoms too deeply nested\n"); return -1; } ret = parse_atoms( atom->data, atom->size, update_chunk_offsets_callback, context); context->depth--; return ret; } return 0; } static void set_atom_size(unsigned char *header, uint32_t header_size, uint64_t size) { switch (header_size) { case 8: AV_WB32(header, size); break; case 16: AV_WB64(header + 8, size); break; } } static void upgrade_stco_atom(upgrade_stco_context_t *context, atom_t *atom) { unsigned char *pos; unsigned char *end; uint64_t new_offset; uint32_t offset_count; uint32_t original_offset; /* Note: not performing validations since they were performed on the first pass */ offset_count = BE_32(atom->data + 4); /* write the header */ memcpy(context->dest, atom->data - atom->header_size, atom->header_size + 8); AV_WB32(context->dest + 4, CO64_ATOM); set_atom_size(context->dest, atom->header_size, atom->header_size + 8 + offset_count * 8); context->dest += atom->header_size + 8; /* write the data */ for (pos = atom->data + 8, end = pos + offset_count * 4; pos < end; pos += 4) { original_offset = BE_32(pos) - context->original_moov_size; new_offset = (uint64_t)original_offset + context->new_moov_size; AV_WB64(context->dest, new_offset); context->dest += 8; } } static int upgrade_stco_callback(void *ctx, atom_t *atom) { upgrade_stco_context_t *context = ctx; unsigned char *start_pos; uint64_t copy_size; switch (atom->type) { case STCO_ATOM: upgrade_stco_atom(context, atom); break; case MOOV_ATOM: case TRAK_ATOM: case MDIA_ATOM: case MINF_ATOM: case STBL_ATOM: /* write the atom header */ memcpy(context->dest, atom->data - atom->header_size, atom->header_size); start_pos = context->dest; context->dest += atom->header_size; /* parse internal atoms*/ if (parse_atoms( atom->data, atom->size, upgrade_stco_callback, context) < 0) { return -1; } /* update the atom size */ set_atom_size(start_pos, atom->header_size, context->dest - start_pos); break; default: copy_size = atom->header_size + atom->size; memcpy(context->dest, atom->data - atom->header_size, copy_size); context->dest += copy_size; break; } return 0; } static int update_moov_atom( unsigned char **moov_atom, uint64_t *moov_atom_size) { update_chunk_offsets_context_t update_context = { 0 }; upgrade_stco_context_t upgrade_context; unsigned char *new_moov_atom; update_context.moov_atom_size = *moov_atom_size; if (parse_atoms( *moov_atom, *moov_atom_size, update_chunk_offsets_callback, &update_context) < 0) { return -1; } if (!update_context.stco_overflow) { return 0; } printf(" upgrading stco atoms to co64...\n"); upgrade_context.new_moov_size = *moov_atom_size + update_context.stco_offset_count * 8 - update_context.stco_data_size; new_moov_atom = malloc(upgrade_context.new_moov_size); if (new_moov_atom == NULL) { fprintf(stderr, "could not allocate %"PRIu64" bytes for updated moov atom\n", upgrade_context.new_moov_size); return -1; } upgrade_context.original_moov_size = *moov_atom_size; upgrade_context.dest = new_moov_atom; if (parse_atoms( *moov_atom, *moov_atom_size, upgrade_stco_callback, &upgrade_context) < 0) { free(new_moov_atom); return -1; } free(*moov_atom); *moov_atom = new_moov_atom; *moov_atom_size = upgrade_context.new_moov_size; if (upgrade_context.dest != *moov_atom + *moov_atom_size) { fprintf(stderr, "unexpected - wrong number of moov bytes written\n"); return -1; } return 0; } int main(int argc, char *argv[]) { FILE *infile = NULL; FILE *outfile = NULL; unsigned char atom_bytes[ATOM_PREAMBLE_SIZE]; uint32_t atom_type = 0; uint64_t atom_size = 0; uint64_t atom_offset = 0; int64_t last_offset; unsigned char *moov_atom = NULL; unsigned char *ftyp_atom = NULL; uint64_t moov_atom_size; uint64_t ftyp_atom_size = 0; int64_t start_offset = 0; unsigned char *copy_buffer = NULL; int bytes_to_copy; uint64_t free_size = 0; uint64_t moov_size = 0; if (argc != 3) { printf("Usage: qt-faststart <infile.mov> <outfile.mov>\n" "Note: alternatively you can use -movflags +faststart in ffmpeg\n"); return 0; } if (!strcmp(argv[1], argv[2])) { fprintf(stderr, "input and output files need to be different\n"); return 1; } infile = fopen(argv[1], "rb"); if (!infile) { perror(argv[1]); goto error_out; } /* traverse through the atoms in the file to make sure that 'moov' is * at the end */ while (!feof(infile)) { if (fread(atom_bytes, ATOM_PREAMBLE_SIZE, 1, infile) != 1) { break; } atom_size = BE_32(&atom_bytes[0]); atom_type = BE_32(&atom_bytes[4]); /* keep ftyp atom */ if (atom_type == FTYP_ATOM) { if (atom_size > MAX_FTYP_ATOM_SIZE) { fprintf(stderr, "ftyp atom size %"PRIu64" too big\n", atom_size); goto error_out; } ftyp_atom_size = atom_size; free(ftyp_atom); ftyp_atom = malloc(ftyp_atom_size); if (!ftyp_atom) { fprintf(stderr, "could not allocate %"PRIu64" bytes for ftyp atom\n", atom_size); goto error_out; } if (fseeko(infile, -ATOM_PREAMBLE_SIZE, SEEK_CUR) || fread(ftyp_atom, atom_size, 1, infile) != 1 || (start_offset = ftello(infile)) < 0) { perror(argv[1]); goto error_out; } } else { int ret; /* 64-bit special case */ if (atom_size == 1) { if (fread(atom_bytes, ATOM_PREAMBLE_SIZE, 1, infile) != 1) { break; } atom_size = BE_64(&atom_bytes[0]); ret = fseeko(infile, atom_size - ATOM_PREAMBLE_SIZE * 2, SEEK_CUR); } else { ret = fseeko(infile, atom_size - ATOM_PREAMBLE_SIZE, SEEK_CUR); } if (ret) { perror(argv[1]); goto error_out; } } printf("%c%c%c%c %10"PRIu64" %"PRIu64"\n", (atom_type >> 24) & 255, (atom_type >> 16) & 255, (atom_type >> 8) & 255, (atom_type >> 0) & 255, atom_offset, atom_size); if ((atom_type != FREE_ATOM) && (atom_type != JUNK_ATOM) && (atom_type != MDAT_ATOM) && (atom_type != MOOV_ATOM) && (atom_type != PNOT_ATOM) && (atom_type != SKIP_ATOM) && (atom_type != WIDE_ATOM) && (atom_type != PICT_ATOM) && (atom_type != UUID_ATOM) && (atom_type != FTYP_ATOM)) { fprintf(stderr, "encountered non-QT top-level atom (is this a QuickTime file?)\n"); break; } atom_offset += atom_size; /* The atom header is 8 (or 16 bytes), if the atom size (which * includes these 8 or 16 bytes) is less than that, we won't be * able to continue scanning sensibly after this atom, so break. */ if (atom_size < 8) break; if (atom_type == MOOV_ATOM) moov_size = atom_size; if (moov_size && atom_type == FREE_ATOM) { free_size += atom_size; atom_type = MOOV_ATOM; atom_size = moov_size; } } if (atom_type != MOOV_ATOM) { printf("last atom in file was not a moov atom\n"); free(ftyp_atom); fclose(infile); return 0; } if (atom_size < 16) { fprintf(stderr, "bad moov atom size\n"); goto error_out; } /* moov atom was, in fact, the last atom in the chunk; load the whole * moov atom */ if (fseeko(infile, -(atom_size + free_size), SEEK_END)) { perror(argv[1]); goto error_out; } last_offset = ftello(infile); if (last_offset < 0) { perror(argv[1]); goto error_out; } moov_atom_size = atom_size; moov_atom = malloc(moov_atom_size); if (!moov_atom) { fprintf(stderr, "could not allocate %"PRIu64" bytes for moov atom\n", atom_size); goto error_out; } if (fread(moov_atom, atom_size, 1, infile) != 1) { perror(argv[1]); goto error_out; } /* this utility does not support compressed atoms yet, so disqualify * files with compressed QT atoms */ if (BE_32(&moov_atom[12]) == CMOV_ATOM) { fprintf(stderr, "this utility does not support compressed moov atoms yet\n"); goto error_out; } /* close; will be re-opened later */ fclose(infile); infile = NULL; if (update_moov_atom(&moov_atom, &moov_atom_size) < 0) { goto error_out; } /* re-open the input file and open the output file */ infile = fopen(argv[1], "rb"); if (!infile) { perror(argv[1]); goto error_out; } if (start_offset > 0) { /* seek after ftyp atom */ if (fseeko(infile, start_offset, SEEK_SET)) { perror(argv[1]); goto error_out; } last_offset -= start_offset; } outfile = fopen(argv[2], "wb"); if (!outfile) { perror(argv[2]); goto error_out; } /* dump the same ftyp atom */ if (ftyp_atom_size > 0) { printf(" writing ftyp atom...\n"); if (fwrite(ftyp_atom, ftyp_atom_size, 1, outfile) != 1) { perror(argv[2]); goto error_out; } } /* dump the new moov atom */ printf(" writing moov atom...\n"); if (fwrite(moov_atom, moov_atom_size, 1, outfile) != 1) { perror(argv[2]); goto error_out; } /* copy the remainder of the infile, from offset 0 -> last_offset - 1 */ bytes_to_copy = MIN(COPY_BUFFER_SIZE, last_offset); copy_buffer = malloc(bytes_to_copy); if (!copy_buffer) { fprintf(stderr, "could not allocate %d bytes for copy_buffer\n", bytes_to_copy); goto error_out; } printf(" copying rest of file...\n"); while (last_offset) { bytes_to_copy = MIN(bytes_to_copy, last_offset); if (fread(copy_buffer, bytes_to_copy, 1, infile) != 1) { perror(argv[1]); goto error_out; } if (fwrite(copy_buffer, bytes_to_copy, 1, outfile) != 1) { perror(argv[2]); goto error_out; } last_offset -= bytes_to_copy; } fclose(infile); fclose(outfile); free(moov_atom); free(ftyp_atom); free(copy_buffer); return 0; error_out: if (infile) fclose(infile); if (outfile) fclose(outfile); free(moov_atom); free(ftyp_atom); free(copy_buffer); return 1; }