// read mp4 header to extract config data
static int read_mp4_header(unsigned long *samplerate_p, unsigned char *channels_p) {
size_t bytes = min(_buf_used(streambuf), _buf_cont_read(streambuf));
char type[5];
u32_t len;
while (bytes >= 8) {
// count trak to find the first playable one
static unsigned trak, play;
u32_t consume;
len = unpackN((u32_t *)streambuf->readp);
memcpy(type, streambuf->readp + 4, 4);
type[4] = '\0';
if (!strcmp(type, "moov")) {
trak = 0;
play = 0;
}
if (!strcmp(type, "trak")) {
trak++;
}
// extract audio config from within esds and pass to DecInit2
if (!strcmp(type, "esds") && bytes > len) {
unsigned config_len;
u8_t *ptr = streambuf->readp + 12;
if (*ptr++ == 0x03) {
mp4_desc_length(&ptr);
ptr += 4;
} else {
ptr += 3;
}
mp4_desc_length(&ptr);
ptr += 13;
if (*ptr++ != 0x05) {
LOG_WARN("error parsing esds");
return -1;
}
config_len = mp4_desc_length(&ptr);
if (NEAAC(a, Init2, a->hAac, ptr, config_len, samplerate_p, channels_p) == 0) {
LOG_DEBUG("playable aac track: %u", trak);
play = trak;
}
}
// extract the total number of samples from stts
if (!strcmp(type, "stts") && bytes > len) {
u32_t i;
u8_t *ptr = streambuf->readp + 12;
u32_t entries = unpackN((u32_t *)ptr);
ptr += 4;
for (i = 0; i < entries; ++i) {
u32_t count = unpackN((u32_t *)ptr);
u32_t size = unpackN((u32_t *)(ptr + 4));
a->sttssamples += count * size;
ptr += 8;
}
LOG_DEBUG("total number of samples contained in stts: " FMT_u64, a->sttssamples);
}
// stash sample to chunk info, assume it comes before stco
if (!strcmp(type, "stsc") && bytes > len && !a->chunkinfo) {
a->stsc = malloc(len - 12);
if (a->stsc == NULL) {
LOG_WARN("malloc fail");
return -1;
}
memcpy(a->stsc, streambuf->readp + 12, len - 12);
}
// build offsets table from stco and stored stsc
if (!strcmp(type, "stco") && bytes > len && play == trak) {
u32_t i;
// extract chunk offsets
u8_t *ptr = streambuf->readp + 12;
u32_t entries = unpackN((u32_t *)ptr);
ptr += 4;
a->chunkinfo = malloc(sizeof(struct chunk_table) * (entries + 1));
if (a->chunkinfo == NULL) {
LOG_WARN("malloc fail");
return -1;
}
for (i = 0; i < entries; ++i) {
a->chunkinfo[i].offset = unpackN((u32_t *)ptr);
a->chunkinfo[i].sample = 0;
ptr += 4;
}
a->chunkinfo[i].sample = 0;
a->chunkinfo[i].offset = 0;
// fill in first sample id for each chunk from stored stsc
if (a->stsc) {
u32_t stsc_entries = unpackN((u32_t *)a->stsc);
u32_t sample = 0;
u32_t last = 0, last_samples = 0;
u8_t *ptr = (u8_t *)a->stsc + 4;
while (stsc_entries--) {
u32_t first = unpackN((u32_t *)ptr);
u32_t samples = unpackN((u32_t *)(ptr + 4));
if (last) {
for (i = last - 1; i < first - 1; ++i) {
a->chunkinfo[i].sample = sample;
sample += last_samples;
}
}
if (stsc_entries == 0) {
for (i = first - 1; i < entries; ++i) {
a->chunkinfo[i].sample = sample;
sample += samples;
}
}
last = first;
last_samples = samples;
ptr += 12;
}
free(a->stsc);
a->stsc = NULL;
}
}
// found media data, advance to start of first chunk and return
if (!strcmp(type, "mdat")) {
_buf_inc_readp(streambuf, 8);
a->pos += 8;
bytes -= 8;
if (play) {
LOG_DEBUG("type: mdat len: %u pos: %u", len, a->pos);
if (a->chunkinfo && a->chunkinfo[0].offset > a->pos) {
u32_t skip = a->chunkinfo[0].offset - a->pos;
LOG_DEBUG("skipping: %u", skip);
if (skip <= bytes) {
_buf_inc_readp(streambuf, skip);
a->pos += skip;
} else {
a->consume = skip;
}
}
a->sample = a->nextchunk = 1;
return 1;
} else {
LOG_DEBUG("type: mdat len: %u, no playable track found", len);
return -1;
}
}
// parse key-value atoms within ilst ---- entries to get encoder padding within iTunSMPB entry for gapless
if (!strcmp(type, "----") && bytes > len) {
u8_t *ptr = streambuf->readp + 8;
u32_t remain = len - 8, size;
if (!memcmp(ptr + 4, "mean", 4) && (size = unpackN((u32_t *)ptr)) < remain) {
ptr += size; remain -= size;
}
if (!memcmp(ptr + 4, "name", 4) && (size = unpackN((u32_t *)ptr)) < remain && !memcmp(ptr + 12, "iTunSMPB", 8)) {
ptr += size; remain -= size;
}
if (!memcmp(ptr + 4, "data", 4) && remain > 16 + 48) {
// data is stored as hex strings: 0 start end samples
u32_t b, c; u64_t d;
if (sscanf((const char *)(ptr + 16), "%x %x %x " FMT_x64, &b, &b, &c, &d) == 4) {
LOG_DEBUG("iTunSMPB start: %u end: %u samples: " FMT_u64, b, c, d);
if (a->sttssamples && a->sttssamples < b + c + d) {
LOG_DEBUG("reducing samples as stts count is less");
d = a->sttssamples - (b + c);
}
a->skip = b;
a->samples = d;
}
}
}
// default to consuming entire box
consume = len;
// read into these boxes so reduce consume
if (!strcmp(type, "moov") || !strcmp(type, "trak") || !strcmp(type, "mdia") || !strcmp(type, "minf") || !strcmp(type, "stbl") ||
!strcmp(type, "udta") || !strcmp(type, "ilst")) {
consume = 8;
}
// special cases which mix mix data in the enclosing box which we want to read into
if (!strcmp(type, "stsd")) consume = 16;
if (!strcmp(type, "mp4a")) consume = 36;
if (!strcmp(type, "meta")) consume = 12;
// consume rest of box if it has been parsed (all in the buffer) or is not one we want to parse
if (bytes >= consume) {
LOG_DEBUG("type: %s len: %u consume: %u", type, len, consume);
_buf_inc_readp(streambuf, consume);
a->pos += consume;
bytes -= consume;
} else if ( !(!strcmp(type, "esds") || !strcmp(type, "stts") || !strcmp(type, "stsc") ||
!strcmp(type, "stco") || !strcmp(type, "----")) ) {
LOG_DEBUG("type: %s len: %u consume: %u - partial consume: %u", type, len, consume, bytes);
_buf_inc_readp(streambuf, bytes);
a->pos += bytes;
a->consume = consume - bytes;
break;
} else {
break;
}
}
return 0;
}
static decode_state faad_decode(void) {
size_t bytes_total;
size_t bytes_wrap;
NeAACDecFrameInfo info;
s32_t *iptr;
bool endstream;
frames_t frames;
LOCK_S;
bytes_total = _buf_used(streambuf);
bytes_wrap = min(bytes_total, _buf_cont_read(streambuf));
if (stream.state <= DISCONNECT && !bytes_total) {
UNLOCK_S;
return DECODE_COMPLETE;
}
if (a->consume) {
u32_t consume = min(a->consume, bytes_wrap);
LOG_DEBUG("consume: %u of %u", consume, a->consume);
_buf_inc_readp(streambuf, consume);
a->pos += consume;
a->consume -= consume;
UNLOCK_S;
return DECODE_RUNNING;
}
if (decode.new_stream) {
int found = 0;
static unsigned char channels;
static unsigned long samplerate;
if (a->type == '2') {
// adts stream - seek for header
while (bytes_wrap >= 2 && (*(streambuf->readp) != 0xFF || (*(streambuf->readp + 1) & 0xF6) != 0xF0)) {
_buf_inc_readp(streambuf, 1);
bytes_total--;
bytes_wrap--;
}
if (bytes_wrap >= 2) {
long n = NEAAC(a, Init, a->hAac, streambuf->readp, bytes_wrap, &samplerate, &channels);
if (n < 0) {
found = -1;
} else {
_buf_inc_readp(streambuf, n);
found = 1;
}
}
} else {
// mp4 - read header
found = read_mp4_header(&samplerate, &channels);
}
if (found == 1) {
LOG_INFO("samplerate: %u channels: %u", samplerate, channels);
bytes_total = _buf_used(streambuf);
bytes_wrap = min(bytes_total, _buf_cont_read(streambuf));
LOCK_O;
LOG_INFO("setting track_start");
output.next_sample_rate = decode_newstream(samplerate, output.supported_rates);
IF_DSD( output.next_dop = false; )
static decode_state faad_decode(void) {
size_t bytes_total;
size_t bytes_wrap;
NeAACDecFrameInfo info;
s32_t *iptr;
bool endstream;
frames_t frames;
LOCK_S;
bytes_total = _buf_used(streambuf);
bytes_wrap = min(bytes_total, _buf_cont_read(streambuf));
if (stream.state <= DISCONNECT && !bytes_total) {
UNLOCK_S;
return DECODE_COMPLETE;
}
if (a->consume) {
u32_t consume = min(a->consume, bytes_wrap);
LOG_DEBUG("consume: %u of %u", consume, a->consume);
_buf_inc_readp(streambuf, consume);
a->pos += consume;
a->consume -= consume;
UNLOCK_S;
return DECODE_RUNNING;
}
if (decode.new_stream) {
int found = 0;
static unsigned char channels;
static unsigned long samplerate;
if (a->type == '2') {
// adts stream - seek for header
while (bytes_wrap >= 2 && (*(streambuf->readp) != 0xFF || (*(streambuf->readp + 1) & 0xF6) != 0xF0)) {
_buf_inc_readp(streambuf, 1);
bytes_total--;
bytes_wrap--;
}
if (bytes_wrap >= 2) {
long n = NEAAC(a, Init, a->hAac, streambuf->readp, bytes_wrap, &samplerate, &channels);
if (n < 0) {
found = -1;
} else {
_buf_inc_readp(streambuf, n);
found = 1;
}
}
} else {
// mp4 - read header
found = read_mp4_header(&samplerate, &channels);
}
if (found == 1) {
LOG_INFO("samplerate: %u channels: %u", samplerate, channels);
bytes_total = _buf_used(streambuf);
bytes_wrap = min(bytes_total, _buf_cont_read(streambuf));
LOCK_O;
LOG_INFO("setting track_start");
output.next_sample_rate = decode_newstream(samplerate, output.max_sample_rate);
output.track_start = outputbuf->writep;
if (output.fade_mode) _checkfade(true);
decode.new_stream = false;
UNLOCK_O;
} else if (found == -1) {
LOG_WARN("error reading stream header");
UNLOCK_S;
return DECODE_ERROR;
} else {
// not finished header parsing come back next time
UNLOCK_S;
return DECODE_RUNNING;
}
}
if (bytes_wrap < WRAPBUF_LEN && bytes_total > WRAPBUF_LEN) {
// make a local copy of frames which may have wrapped round the end of streambuf
u8_t buf[WRAPBUF_LEN];
memcpy(buf, streambuf->readp, bytes_wrap);
memcpy(buf + bytes_wrap, streambuf->buf, WRAPBUF_LEN - bytes_wrap);
iptr = NEAAC(a, Decode, a->hAac, &info, buf, WRAPBUF_LEN);
} else {
iptr = NEAAC(a, Decode, a->hAac, &info, streambuf->readp, bytes_wrap);
}
if (info.error) {
LOG_WARN("error: %u %s", info.error, NEAAC(a, GetErrorMessage, info.error));
}
endstream = false;
// mp4 end of chunk - skip to next offset
if (a->chunkinfo && a->chunkinfo[a->nextchunk].offset && a->sample++ == a->chunkinfo[a->nextchunk].sample) {
if (a->chunkinfo[a->nextchunk].offset > a->pos) {
u32_t skip = a->chunkinfo[a->nextchunk].offset - a->pos;
if (skip != info.bytesconsumed) {
LOG_DEBUG("skipping to next chunk pos: %u consumed: %u != skip: %u", a->pos, info.bytesconsumed, skip);
}
if (bytes_total >= skip) {
_buf_inc_readp(streambuf, skip);
a->pos += skip;
} else {
a->consume = skip;
}
a->nextchunk++;
} else {
LOG_ERROR("error: need to skip backwards!");
endstream = true;
}
// adts and mp4 when not at end of chunk
} else if (info.bytesconsumed != 0) {
_buf_inc_readp(streambuf, info.bytesconsumed);
a->pos += info.bytesconsumed;
// error which doesn't advance streambuf - end
} else {
endstream = true;
}
UNLOCK_S;
if (endstream) {
LOG_WARN("unable to decode further");
return DECODE_ERROR;
}
if (!info.samples) {
a->empty = true;
return DECODE_RUNNING;
}
frames = info.samples / info.channels;
if (a->skip) {
u32_t skip;
if (a->empty) {
a->empty = false;
a->skip -= frames;
LOG_DEBUG("gapless: first frame empty, skipped %u frames at start", frames);
}
skip = min(frames, a->skip);
LOG_DEBUG("gapless: skipping %u frames at start", skip);
frames -= skip;
a->skip -= skip;
iptr += skip * info.channels;
}
if (a->samples) {
if (a->samples < frames) {
LOG_DEBUG("gapless: trimming %u frames from end", frames - a->samples);
frames = (frames_t)a->samples;
}
a->samples -= frames;
}
LOG_SDEBUG("write %u frames", frames);
LOCK_O_direct;
while (frames > 0) {
frames_t f;
frames_t count;
s32_t *optr;
IF_DIRECT(
f = _buf_cont_write(outputbuf) / BYTES_PER_FRAME;
optr = (s32_t *)outputbuf->writep;
);
IF_PROCESS(
f = process.max_in_frames;
optr = (s32_t *)process.inbuf;
);
