Author: titmuss
Date: Fri May 16 05:52:53 2008
New Revision: 2469
URL: http://svn.slimdevices.com?rev=2469&root=Jive&view=rev
Log:
Bug: N/A
Description:
Add support for mp3 gapless playback.
Modified:
7.2/trunk/squeezeplay/src/squeezeplay/src/audio/decode/decode_mad.c
7.2/trunk/squeezeplay/src/squeezeplay/src/audio/decode/decode_output.c
7.2/trunk/squeezeplay/src/squeezeplay/src/audio/decode/decode_priv.h
Modified: 7.2/trunk/squeezeplay/src/squeezeplay/src/audio/decode/decode_mad.c
URL:
http://svn.slimdevices.com/7.2/trunk/squeezeplay/src/squeezeplay/src/audio/decode/decode_mad.c?rev=2469&root=Jive&r1=2468&r2=2469&view=diff
==============================================================================
--- 7.2/trunk/squeezeplay/src/squeezeplay/src/audio/decode/decode_mad.c
(original)
+++ 7.2/trunk/squeezeplay/src/squeezeplay/src/audio/decode/decode_mad.c Fri May
16 05:52:53 2008
@@ -31,6 +31,10 @@
u8_t *input_buffer;
sample_t *output_buffer;
u8_t *guard_pointer;
+
+ u32_t frames;
+ u32_t encoder_delay;
+ u32_t encoder_padding;
enum {
MAD_STATE_OK = 0,
@@ -43,6 +47,95 @@
};
+#define XING_MAGIC ( ('X' << 24) | ('i' << 16) | ('n' << 8) | 'g' )
+#define INFO_MAGIC ( ('I' << 24) | ('n' << 16) | ('f' << 8) | 'o' )
+#define LAME_MAGIC ( ('L' << 24) | ('A' << 16) | ('M' << 8) | 'E' )
+
+#define XING_FRAMES 0x01
+#define XING_BYTES 0x02
+#define XING_TOC 0x04
+#define XING_SCALE 0x08
+
+static void xing_parse(struct decode_mad *self) {
+ struct mad_bitptr ptr = self->stream.anc_ptr;
+ unsigned int bitlen = self->stream.anc_bitlen;
+
+ if (bitlen < 64) {
+ DEBUG_TRACE("no xing header");
+ return;
+ }
+
+ u32_t magic = mad_bit_read(&ptr, 32);
+ DEBUG_TRACE("xing magic %x", magic);
+ if (magic != XING_MAGIC && magic != INFO_MAGIC) {
+ return;
+ }
+
+ u32_t flags = mad_bit_read(&ptr, 32);
+ bitlen -= 64;
+
+ // skip traditional xing vbr tag data
+ if (flags & XING_FRAMES) {
+ DEBUG_TRACE("skipping xing frames");
+ if (bitlen < 32) {
+ return;
+ }
+ mad_bit_skip(&ptr, 32);
+ bitlen -= 32;
+ }
+ if (flags & XING_BYTES) {
+ DEBUG_TRACE("skipping xing bytes");
+ if (bitlen < 32) {
+ return;
+ }
+ mad_bit_skip(&ptr, 32);
+ bitlen -= 32;
+ }
+ if (flags & XING_TOC) {
+ DEBUG_TRACE("skipping xing toc");
+ if (bitlen < 800) {
+ return;
+ }
+ mad_bit_skip(&ptr, 800);
+ bitlen -= 800;
+ }
+ if (flags & XING_SCALE) {
+ DEBUG_TRACE("skipping xing scale");
+ if (bitlen < 32) {
+ return;
+ }
+ mad_bit_skip(&ptr, 32);
+ bitlen -= 32;
+ }
+
+ if (bitlen < 72) {
+ DEBUG_TRACE("no lame header");
+ return;
+ }
+
+ magic = mad_bit_read(&ptr, 32);
+ mad_bit_skip(&ptr, 40);
+ bitlen -= 72;
+
+ DEBUG_TRACE("lame magic %x", magic);
+ if (magic != LAME_MAGIC) {
+ return;
+ }
+
+ if (bitlen < 120) {
+ return;
+ }
+
+ mad_bit_skip(&ptr, 96);
+
+ self->encoder_delay = mad_bit_read(&ptr, 12);
+ self->encoder_padding = mad_bit_read(&ptr, 12);
+
+ DEBUG_TRACE("encoder delay %d", self->encoder_delay);
+ DEBUG_TRACE("encoder padding %d", self->encoder_padding);
+}
+
+
static void decode_mad_frame(struct decode_mad *self) {
size_t read_max, read_num, remaining;
u8_t *read_start;
@@ -82,7 +175,7 @@
/* If we're at the end of the input file, write
* out the buffer guard.
*/
- self->guard_pointer = read_start + read_num;
+ self->guard_pointer = read_start;
memset(self->guard_pointer, 0,
MAD_BUFFER_GUARD);
read_num += MAD_BUFFER_GUARD;
}
@@ -129,49 +222,68 @@
static void decode_mad_output(struct decode_mad *self) {
+ struct mad_pcm *pcm;
sample_t *buf;
mad_fixed_t *left, *right;
- int i;
+ int i, offset = 0;
+
+ pcm = &self->synth.pcm;
self->sample_rate = self->frame.header.samplerate;
- if (!decode_output_can_write(self->synth.pcm.length * 2 *
sizeof(sample_t), self->sample_rate)) {
+ if (!decode_output_can_write(pcm->length * 2 * sizeof(sample_t),
self->sample_rate)) {
self->state = MAD_STATE_PCM_READY;
return;
}
- // XXXX parse xing header
-
- buf = self->output_buffer;
-
- left = self->synth.pcm.samples[0];
- right = self->synth.pcm.samples[1];
-
- if (self->synth.pcm.channels == 2) {
- /* stero */
- for (i=0; i<self->synth.pcm.length; i++) {
- *buf++ = *left++ << (32 - MAD_F_FRACBITS - 1);
- *buf++ = *right++ << (32 - MAD_F_FRACBITS - 1);
- }
+ /* parse xing header */
+ if (self->frames++ == 0) {
+ xing_parse(self);
+ self->encoder_delay *= pcm->channels;
}
else {
- /* mono */
- sample_t s;
-
- for (i=0; i<self->synth.pcm.length; i++) {
- s = *left++ << (32 - MAD_F_FRACBITS - 1);
-
- *buf++ = s;
- *buf++ = s;
- }
- }
-
- decode_output_samples(self->output_buffer,
- self->synth.pcm.length,
- self->sample_rate,
- FALSE,
- TRUE,
- FALSE);
+ buf = self->output_buffer;
+
+ left = pcm->samples[0];
+ right = pcm->samples[1];
+
+ if (pcm->channels == 2) {
+ /* stero */
+ for (i=0; i<pcm->length; i++) {
+ *buf++ = *left++ << (32 - MAD_F_FRACBITS - 1);
+ *buf++ = *right++ << (32 - MAD_F_FRACBITS - 1);
+ }
+ }
+ else {
+ /* mono */
+ sample_t s;
+
+ for (i=0; i<pcm->length; i++) {
+ s = *left++ << (32 - MAD_F_FRACBITS - 1);
+
+ *buf++ = s;
+ *buf++ = s;
+ }
+ }
+
+ /* skip samples for the encoder delay */
+ if (self->encoder_delay) {
+ offset = self->encoder_delay;
+ if (offset > pcm->length) {
+ offset = pcm->length;
+ }
+ self->encoder_delay -= offset;
+
+ DEBUG_TRACE("Skip encoder_delay=%d pcm->length=%d
offset=%d", self->encoder_delay, pcm->length, offset);
+ }
+
+ decode_output_samples(self->output_buffer + (offset *
sizeof(sample_t)),
+ pcm->length - offset,
+ self->sample_rate,
+ FALSE,
+ TRUE,
+ FALSE);
+ }
/* If we've come to the guard pointer, we're done */
if (self->stream.this_frame == self->guard_pointer) {
@@ -179,7 +291,10 @@
self->state = MAD_STATE_END_OF_FILE;
- // XXXX remove padding?
+ if (self->encoder_padding) {
+ DEBUG_TRACE("Remove encoder padding=%d",
self->encoder_padding);
+ decode_output_remove_padding(self->encoder_padding,
self->sample_rate);
+ }
}
else {
self->state = MAD_STATE_OK;
@@ -243,6 +358,10 @@
/* Assume we aren't changing sample rates until proven wrong */
self->sample_rate = decode_output_samplerate();
+
+ /* Don't check for CRC errors (bug #2527) */
+ // XXXX this needs a patch to libmad
+ //decoder->stream.options = MAD_OPTION_ZEROCRC;
return self;
}
Modified: 7.2/trunk/squeezeplay/src/squeezeplay/src/audio/decode/decode_output.c
URL:
http://svn.slimdevices.com/7.2/trunk/squeezeplay/src/squeezeplay/src/audio/decode/decode_output.c?rev=2469&root=Jive&r1=2468&r2=2469&view=diff
==============================================================================
--- 7.2/trunk/squeezeplay/src/squeezeplay/src/audio/decode/decode_output.c
(original)
+++ 7.2/trunk/squeezeplay/src/squeezeplay/src/audio/decode/decode_output.c Fri
May 16 05:52:53 2008
@@ -166,6 +166,48 @@
}
+/* This removes padding samples from the buffer (for gapless mp3 playback). */
+void decode_output_remove_padding(u32_t nsamples, u32_t sample_rate) {
+#if 0
+ int numerator, denominator;
+ u32_t resampled_rate;
+#endif
+ size_t buffer_size;
+
+ buffer_size = SAMPLES_TO_BYTES(nsamples);
+
+#if 0
+ // XXXX full port from ip3k
+ u32_t resampled_rate = decode_output_scaled_samplerate(sample_rate,
&numerator, &denominator);
+ if (numerator != 1) {
+ buffer_size /= numerator;
+ }
+ buffer_size *= denominator;
+#endif
+
+ DEBUG_TRACE("Removing %d bytes padding from buffer", buffer_size);
+
+ fifo_lock(&decode_fifo);
+
+ /* have we already started playing the padding? */
+ if (fifo_bytes_used(&decode_fifo) <= buffer_size) {
+ fifo_unlock(&decode_fifo);
+
+ DEBUG_TRACE("- already playing padding");
+ return;
+ }
+
+ if (decode_fifo.wptr < buffer_size) {
+ decode_fifo.wptr += decode_fifo.size - buffer_size;
+ }
+ else {
+ decode_fifo.wptr -= buffer_size;
+ }
+
+ fifo_unlock(&decode_fifo);
+}
+
+
int decode_output_samplerate() {
return current_sample_rate;
}
Modified: 7.2/trunk/squeezeplay/src/squeezeplay/src/audio/decode/decode_priv.h
URL:
http://svn.slimdevices.com/7.2/trunk/squeezeplay/src/squeezeplay/src/audio/decode/decode_priv.h?rev=2469&root=Jive&r1=2468&r2=2469&view=diff
==============================================================================
--- 7.2/trunk/squeezeplay/src/squeezeplay/src/audio/decode/decode_priv.h
(original)
+++ 7.2/trunk/squeezeplay/src/squeezeplay/src/audio/decode/decode_priv.h Fri
May 16 05:52:53 2008
@@ -48,6 +48,8 @@
bool_t need_scaling, bool_t
start_immediately,
bool_t copyright_asserted);
+extern void decode_output_remove_padding(u32_t nsamples, u32_t sample_rate);
+
extern int decode_output_samplerate();
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