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ffmpeg/qt-faststart.c

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/*
* qt-faststart.c, v0.1
* 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.
*
* Compile this program using:
* cc qt-faststart.c -o qt-faststart
* 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>
#define BE_16(x) ((((uint8_t*)(x))[0] << 8) | ((uint8_t*)(x))[1])
#define BE_32(x) ((((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 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 CMOV_ATOM QT_ATOM('c', 'm', 'o', 'v')
#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 1024
int main(int argc, char *argv[])
{
FILE *infile;
FILE *outfile;
unsigned char atom_bytes[ATOM_PREAMBLE_SIZE];
uint32_t atom_type = 0;
uint64_t atom_size;
uint64_t last_offset;
unsigned char *moov_atom;
uint64_t moov_atom_size;
uint64_t i, j;
uint32_t offset_count;
uint64_t current_offset;
unsigned char copy_buffer[COPY_BUFFER_SIZE];
int bytes_to_copy;
if (argc != 3) {
printf ("Usage: qt-faststart <infile.mov> <outfile.mov>\n");
return 0;
}
infile = fopen(argv[1], "rb");
if (!infile) {
perror(argv[1]);
return 1;
}
/* 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]);
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 != FTYP_ATOM)) {
printf ("encountered non-QT top-level atom (is this a Quicktime file?)\n");
break;
}
/* 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]);
fseek(infile, atom_size - ATOM_PREAMBLE_SIZE * 2, SEEK_CUR);
} else {
fseek(infile, atom_size - ATOM_PREAMBLE_SIZE, SEEK_CUR);
}
}
if (atom_type != MOOV_ATOM) {
printf ("last atom in file was not a moov atom\n");
fclose(infile);
return 0;
}
/* moov atom was, in fact, the last atom in the chunk; load the whole
* moov atom */
fseek(infile, -atom_size, SEEK_END);
last_offset = (uint64_t)ftell(infile);
moov_atom_size = atom_size;
moov_atom = malloc(moov_atom_size);
if (!moov_atom) {
printf ("could not allocate 0x%llX byte for moov atom\n",
atom_size);
fclose(infile);
return 1;
}
if (fread(moov_atom, atom_size, 1, infile) != 1) {
perror(argv[1]);
free(moov_atom);
fclose(infile);
return 1;
}
/* this utility does not support compressed atoms yet, so disqualify
* files with compressed QT atoms */
if (BE_32(&moov_atom[12]) == CMOV_ATOM) {
printf ("this utility does not support compressed moov atoms yet\n");
free(moov_atom);
fclose(infile);
return 1;
}
/* close; will be re-opened later */
fclose(infile);
/* crawl through the moov chunk in search of stco or co64 atoms */
for (i = 4; i < moov_atom_size - 4; i++) {
atom_type = BE_32(&moov_atom[i]);
if (atom_type == STCO_ATOM) {
printf (" patching stco atom...\n");
atom_size = BE_32(&moov_atom[i - 4]);
if (i + atom_size - 4 > moov_atom_size) {
printf (" bad atom size\n");
free(moov_atom);
return 1;
}
offset_count = BE_32(&moov_atom[i + 8]);
for (j = 0; j < offset_count; j++) {
current_offset = BE_32(&moov_atom[i + 12 + j * 4]);
current_offset += moov_atom_size;
moov_atom[i + 12 + j * 4 + 0] = (current_offset >> 24) & 0xFF;
moov_atom[i + 12 + j * 4 + 1] = (current_offset >> 16) & 0xFF;
moov_atom[i + 12 + j * 4 + 2] = (current_offset >> 8) & 0xFF;
moov_atom[i + 12 + j * 4 + 3] = (current_offset >> 0) & 0xFF;
}
i += atom_size - 4;
} else if (atom_type == CO64_ATOM) {
printf (" patching co64 atom...\n");
atom_size = BE_32(&moov_atom[i - 4]);
if (i + atom_size - 4 > moov_atom_size) {
printf (" bad atom size\n");
free(moov_atom);
return 1;
}
offset_count = BE_32(&moov_atom[i + 8]);
for (j = 0; j < offset_count; j++) {
current_offset = BE_64(&moov_atom[i + 12 + j * 8]);
current_offset += moov_atom_size;
moov_atom[i + 12 + j * 8 + 0] = (current_offset >> 56) & 0xFF;
moov_atom[i + 12 + j * 8 + 1] = (current_offset >> 48) & 0xFF;
moov_atom[i + 12 + j * 8 + 2] = (current_offset >> 40) & 0xFF;
moov_atom[i + 12 + j * 8 + 3] = (current_offset >> 32) & 0xFF;
moov_atom[i + 12 + j * 8 + 4] = (current_offset >> 24) & 0xFF;
moov_atom[i + 12 + j * 8 + 5] = (current_offset >> 16) & 0xFF;
moov_atom[i + 12 + j * 8 + 6] = (current_offset >> 8) & 0xFF;
moov_atom[i + 12 + j * 8 + 7] = (current_offset >> 0) & 0xFF;
}
i += atom_size - 4;
}
}
/* re-open the input file and open the output file */
infile = fopen(argv[1], "rb");
if (!infile) {
perror(argv[1]);
free(moov_atom);
return 1;
}
outfile = fopen(argv[2], "wb");
if (!outfile) {
perror(argv[2]);
fclose(outfile);
free(moov_atom);
return 1;
}
/* dump the new moov atom */
printf (" writing moov aton...\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 */
printf (" copying rest of file...\n");
while (last_offset) {
if (last_offset > COPY_BUFFER_SIZE)
bytes_to_copy = COPY_BUFFER_SIZE;
else
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);
return 0;
error_out:
fclose(infile);
fclose(outfile);
free(moov_atom);
return 1;
}
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