#include "mp4.h"
struct mp4_track {
- uint16_t channelCount;
- uint16_t sampleRate;
+ /* mp4a */
+ uint16_t channel_count;
+ uint16_t sample_rate;
/* stsz */
uint32_t stsz_sample_size;
uint32_t stco_entry_count;
uint32_t *stco_chunk_offset;
- uint32_t timeScale;
+ /* mdhd */
+ uint32_t time_scale;
uint64_t duration;
};
return ret;
}
-static bool atom_compare(int8_t a1, int8_t b1, int8_t c1, int8_t d1,
- int8_t a2, int8_t b2, int8_t c2, int8_t d2)
+#define ATOM_ITEMS \
+ ATOM_ITEM(MOOV, 'm', 'o', 'o', 'v') \
+ ATOM_ITEM(TRAK, 't', 'r', 'a', 'k') \
+ ATOM_ITEM(MDIA, 'm', 'd', 'i', 'a') \
+ ATOM_ITEM(MINF, 'm', 'i', 'n', 'f') \
+ ATOM_ITEM(STBL, 's', 't', 'b', 'l') \
+ ATOM_ITEM(UDTA, 'u', 'd', 't', 'a') \
+ ATOM_ITEM(ILST, 'i', 'l', 's', 't') /* iTunes Metadata list */ \
+ ATOM_ITEM(ARTIST, 0xa9, 'A', 'R', 'T') \
+ ATOM_ITEM(TITLE, 0xa9, 'n', 'a', 'm') \
+ ATOM_ITEM(ALBUM, 0xa9, 'a', 'l', 'b') \
+ ATOM_ITEM(DATE, 0xa9, 'd', 'a', 'y') \
+ ATOM_ITEM(COMMENT, 0xa9, 'c', 'm', 't') \
+ ATOM_ITEM(MDHD, 'm', 'd', 'h', 'd') /* track header */ \
+ ATOM_ITEM(STSD, 's', 't', 's', 'd') /* sample description box */ \
+ ATOM_ITEM(STTS, 's', 't', 't', 's') /* time to sample box */ \
+ ATOM_ITEM(STSZ, 's', 't', 's', 'z') /* sample size box */ \
+ ATOM_ITEM(STCO, 's', 't', 'c', 'o') /* chunk offset box */ \
+ ATOM_ITEM(STSC, 's', 't', 's', 'c') /* sample to chunk box */ \
+ ATOM_ITEM(MP4A, 'm', 'p', '4', 'a') \
+ ATOM_ITEM(META, 'm', 'e', 't', 'a') /* iTunes Metadata box */ \
+ ATOM_ITEM(DATA, 'd', 'a', 't', 'a') /* iTunes Metadata data box */ \
+
+#define ATOM_ITEM(_name, a, b, c, d) ATOM_ ## _name,
+enum atom {ATOM_ITEMS};
+#undef ATOM_ITEM
+
+static uint8_t atom_name_to_type(uint8_t *p)
{
- return a1 == a2 && b1 == b2 && c1 == c2 && d1 == d2;
-}
-
-enum atoms {
- /* atoms with subatoms */
- ATOM_MOOV,
- ATOM_TRAK,
- ATOM_MDIA,
- ATOM_MINF,
- ATOM_STBL,
- ATOM_UDTA,
- ATOM_ILST, /* iTunes Metadata list */
- ATOM_TITLE,
- ATOM_ARTIST,
- ATOM_ALBUM,
- ATOM_DATE,
- ATOM_COMMENT,
-
- /* atoms without subatoms */
- ATOM_MDHD, /* track header */
- ATOM_STSD, /* sample description box */
- ATOM_STTS, /* time to sample box */
- ATOM_STSZ, /* sample size box */
- ATOM_STCO, /* chunk offset box */
- ATOM_STSC, /* sample to chunk box */
- ATOM_MP4A,
- ATOM_META, /* iTunes Metadata box */
- ATOM_DATA, /* iTunes Metadata data box */
- ATOM_UNKNOWN = 255
-};
-
-#define COPYRIGHT_SYMBOL ((int8_t)0xA9)
-
-static uint8_t atom_name_to_type(int8_t a, int8_t b, int8_t c, int8_t d)
-{
- if (a == 'm') {
- if (atom_compare(a, b, c, d, 'm', 'o', 'o', 'v'))
- return ATOM_MOOV;
- else if (atom_compare(a, b, c, d, 'm', 'i', 'n', 'f'))
- return ATOM_MINF;
- else if (atom_compare(a, b, c, d, 'm', 'd', 'i', 'a'))
- return ATOM_MDIA;
- else if (atom_compare(a, b, c, d, 'm', 'd', 'h', 'd'))
- return ATOM_MDHD;
- else if (atom_compare(a, b, c, d, 'm', 'p', '4', 'a'))
- return ATOM_MP4A;
- else if (atom_compare(a, b, c, d, 'm', 'e', 't', 'a'))
- return ATOM_META;
- } else if (a == 't') {
- if (atom_compare(a, b, c, d, 't', 'r', 'a', 'k'))
- return ATOM_TRAK;
- } else if (a == 's') {
- if (atom_compare(a, b, c, d, 's', 't', 'b', 'l'))
- return ATOM_STBL;
- else if (atom_compare(a, b, c, d, 's', 't', 's', 'd'))
- return ATOM_STSD;
- else if (atom_compare(a, b, c, d, 's', 't', 't', 's'))
- return ATOM_STTS;
- else if (atom_compare(a, b, c, d, 's', 't', 'c', 'o'))
- return ATOM_STCO;
- else if (atom_compare(a, b, c, d, 's', 't', 's', 'c'))
- return ATOM_STSC;
- else if (atom_compare(a, b, c, d, 's', 't', 's', 'z'))
- return ATOM_STSZ;
- } else if (a == COPYRIGHT_SYMBOL) {
- if (atom_compare(a, b, c, d, COPYRIGHT_SYMBOL, 'n', 'a', 'm'))
- return ATOM_TITLE;
- else if (atom_compare(a, b, c, d, COPYRIGHT_SYMBOL, 'A', 'R', 'T'))
- return ATOM_ARTIST;
- else if (atom_compare(a, b, c, d, COPYRIGHT_SYMBOL, 'a', 'l', 'b'))
- return ATOM_ALBUM;
- else if (atom_compare(a, b, c, d, COPYRIGHT_SYMBOL, 'd', 'a', 'y'))
- return ATOM_DATE;
- else if (atom_compare(a, b, c, d, COPYRIGHT_SYMBOL, 'c', 'm', 't'))
- return ATOM_COMMENT;
- }
- if (atom_compare(a, b, c, d, 'u', 'd', 't', 'a'))
- return ATOM_UDTA;
- else if (atom_compare(a, b, c, d, 'i', 'l', 's', 't'))
- return ATOM_ILST;
- else if (atom_compare(a, b, c, d, 'd', 'a', 't', 'a'))
- return ATOM_DATA;
- else
- return ATOM_UNKNOWN;
+ #define ATOM_VALUE(a, b, c, d) ((a << 24) + (b << 16) + (c << 8) + d)
+ #define ATOM_ITEM(_name, a, b, c, d) \
+ {.name = # _name, .val = ATOM_VALUE(a, b, c, d)},
+ static const struct {
+ const char *name;
+ uint32_t val;
+ } atom_table[] = {ATOM_ITEMS};
+ #undef ATOM_ITEM
+ uint32_t val = read_u32_be(p);
+
+ for (uint8_t n = 0; n < ARRAY_SIZE(atom_table); n++)
+ if (val == atom_table[n].val)
+ return n;
+ return 255;
}
/* read atom header, atom size is returned with header included. */
{
uint32_t size;
int ret;
- int8_t atom_header[8];
+ uint8_t atom_header[8];
ret = read_data(f, atom_header, 8);
if (ret <= 0)
if (atom_size)
*atom_size = size;
}
- *atom_type = atom_name_to_type(atom_header[4], atom_header[5],
- atom_header[6], atom_header[7]);
+ *atom_type = atom_name_to_type(atom_header + 4);
return 1;
}
ret = read_int32(f, NULL); /* reserved */
if (ret <= 0)
return ret;
- ret = read_int16(f, &t->channelCount);
+ ret = read_int16(f, &t->channel_count);
if (ret <= 0)
return ret;
ret = read_int16(f, NULL);
ret = read_int16(f, NULL);
if (ret <= 0)
return ret;
- return read_int16(f, &t->sampleRate);
+ return read_int16(f, &t->sample_rate);
}
static int read_stsd(struct mp4 *f)
ret = read_int64(f, NULL); /* modification-time */
if (ret <= 0)
return ret;
- ret = read_int32(f, &t->timeScale);
+ ret = read_int32(f, &t->time_scale);
if (ret <= 0)
return ret;
ret = read_int64(f, &t->duration);
ret = read_int32(f, NULL); /* modification-time */
if (ret <= 0)
return ret;
- ret = read_int32(f, &t->timeScale);
+ ret = read_int32(f, &t->time_scale);
if (ret <= 0)
return ret;
ret = read_int32(f, &temp);
{
const struct mp4_track *t = f->audio_track;
- if (t->timeScale == 0)
+ if (t->time_scale == 0)
return 0;
- return t->duration * 1000 / t->timeScale;
+ return t->duration * 1000 / t->time_scale;
}
int mp4_set_sample_position(struct mp4 *f, int32_t sample)
uint32_t mp4_get_sample_rate(const struct mp4 *f)
{
- return f->audio_track->sampleRate;
+ return f->audio_track->sample_rate;
}
uint32_t mp4_get_channel_count(const struct mp4 *f)
{
- return f->audio_track->channelCount ;
+ return f->audio_track->channel_count;
}
int32_t mp4_num_samples(const struct mp4 *f)
}
}
-static uint32_t fix_byte_order_32(uint32_t src)
-{
- return read_u32_be(&src);
-}
-
static void *modify_moov(struct mp4 *f, uint32_t *out_size)
{
int ret;
ret = read_int32(f, &tmp);
if (ret <= 0)
return NULL;
- *(uint32_t *)p_out = fix_byte_order_32(tmp + size_delta);
+ write_u32_be(p_out, tmp + size_delta);
p_out += 4;
ret = read_data(f, p_out, 4);
if (ret <= 0)
ret = read_int32(f, &tmp);
if (ret <= 0)
return NULL;
- *(uint32_t *)p_out = fix_byte_order_32(tmp + size_delta);
+ write_u32_be(p_out, tmp + size_delta);
p_out += 4;
ret = read_data(f, p_out, 4);
if (ret <= 0)
ret = read_int32(f, &tmp);
if (ret <= 0)
return NULL;
- *(uint32_t *)p_out = fix_byte_order_32(tmp + size_delta);
+ write_u32_be(p_out, tmp + size_delta);
p_out += 4;
ret = read_data(f, p_out, 4);
if (ret <= 0)
mp4_close(f);
return 0;
}
- /* copy moov atom to end of the file */
if (f->last_atom != ATOM_MOOV) {
- char *free_data = "free";
-
- /* rename old moov to free */
set_position(f, f->moov_offset + 4);
- write_data(f, free_data, 4);
-
- set_position(f, f->file_size);
- write_int32(f, new_moov_size + 8);
- write_data(f, "moov", 4);
- write_data(f, new_moov_data, new_moov_size);
- } else {
+ write_data(f, "free", 4); /* rename old moov to free */
+ set_position(f, f->file_size); /* write new moov atom at EOF */
+ } else /* overwrite old moov atom */
set_position(f, f->moov_offset);
- write_int32(f, new_moov_size + 8);
- write_data(f, "moov", 4);
- write_data(f, new_moov_data, new_moov_size);
- }
+ write_int32(f, new_moov_size + 8);
+ write_data(f, "moov", 4);
+ write_data(f, new_moov_data, new_moov_size);
free(new_moov_data);
f->cb->truncate(f->cb->user_data);
return 1;