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mad: simplify parsing code

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Also fixes #671455 (expected at least).
This commit is contained in:
Mark Nauwelaerts 2012-03-13 18:27:51 +01:00
parent 110a993cc9
commit 6d44ed77a4
1 changed files with 88 additions and 117 deletions
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205
ext/mad/gstmad.c
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@ -278,9 +278,9 @@ gst_mad_parse (GstAudioDecoder * dec, GstAdapter * adapter,
{
GstMad *mad;
GstFlowReturn ret = GST_FLOW_UNEXPECTED;
gint av, size, offset, prev_offset, consumed = 0;
gint av, size, offset;
const guint8 *data;
gboolean eos;
gboolean eos, sync;
GstBuffer *guard = NULL;
mad = GST_MAD (dec);
@ -288,7 +288,9 @@ gst_mad_parse (GstAudioDecoder * dec, GstAdapter * adapter,
av = gst_adapter_available (adapter);
data = gst_adapter_peek (adapter, av);
gst_audio_decoder_get_parse_state (dec, NULL, &eos);
gst_audio_decoder_get_parse_state (dec, &sync, &eos);
GST_LOG_OBJECT (mad, "parse state sync %d, eos %d", sync, eos);
if (eos) {
/* This is one streaming hack right there.
* mad will not decode the last frame if it is not followed by
@ -312,130 +314,99 @@ gst_mad_parse (GstAudioDecoder * dec, GstAdapter * adapter,
* if a frame is found (and also decoded), subsequent handle_frame
* only needs to synthesize it */
prev_offset = -1;
offset = 0;
while (offset < av) {
size = MIN (MAD_BUFFER_MDLEN * 3, av - offset);
size = 0;
/* check for mad asking too much */
if (offset == prev_offset) {
if (G_UNLIKELY (offset + size < av)) {
/* mad should not do this, so really fatal */
GST_ELEMENT_ERROR (mad, STREAM, DECODE, (NULL),
("mad claims to need more data than %u bytes", size));
ret = GST_FLOW_ERROR;
goto exit;
} else {
resume:
if (G_UNLIKELY (offset + MAD_BUFFER_GUARD > av))
goto exit;
GST_LOG_OBJECT (mad, "setup mad stream at offset %d (of av %d)", offset, av);
mad_stream_buffer (&mad->stream, data + offset, av - offset);
/* convey sync idea to mad */
mad->stream.sync = sync;
/* if we get back here, lost sync anyway */
sync = FALSE;
while (TRUE) {
GST_LOG_OBJECT (mad, "decoding the header now");
if (mad_header_decode (&mad->frame.header, &mad->stream) == -1) {
/* HACK it seems mad reports wrong error when it is trying to determine
* free bitrate and scanning for next header */
if (mad->stream.error == MAD_ERROR_LOSTSYNC) {
const guint8 *ptr = mad->stream.this_frame;
guint32 header;
if (ptr >= data && ptr < data + av) {
header = GST_READ_UINT32_BE (ptr);
/* looks like possible freeform header with not much data */
if (((header & 0xFFE00000) == 0xFFE00000) &&
(((header >> 12) & 0xF) == 0x0) && (av < 4096)) {
GST_DEBUG_OBJECT (mad, "overriding freeform LOST_SYNC to BUFLEN");
mad->stream.error = MAD_ERROR_BUFLEN;
}
}
}
if (mad->stream.error == MAD_ERROR_BUFLEN) {
GST_LOG_OBJECT (mad, "not enough data, getting more");
offset = mad->stream.next_frame - data;
break;
}
}
/* only feed that much to mad at a time */
mad_stream_buffer (&mad->stream, data + offset, size);
prev_offset = offset;
while (offset - prev_offset < size) {
consumed = 0;
GST_LOG_OBJECT (mad, "decoding the header now");
if (mad_header_decode (&mad->frame.header, &mad->stream) == -1) {
/* HACK it seems mad reports wrong error when it is trying to determine
* free bitrate and scanning for next header */
if (mad->stream.error == MAD_ERROR_LOSTSYNC) {
const guint8 *ptr = mad->stream.this_frame;
guint32 header;
if (ptr >= data && ptr < data + av) {
header = GST_READ_UINT32_BE (ptr);
/* looks like possible freeform header with not much data */
if (((header & 0xFFE00000) == 0xFFE00000) &&
(((header >> 12) & 0xF) == 0x0) && (av < 4096)) {
GST_DEBUG_OBJECT (mad, "overriding freeform LOST_SYNC to BUFLEN");
mad->stream.error = MAD_ERROR_BUFLEN;
}
}
}
if (mad->stream.error == MAD_ERROR_BUFLEN) {
GST_LOG_OBJECT (mad,
"not enough data in tempbuffer (%d), breaking to get more", size);
break;
} else {
GST_WARNING_OBJECT (mad, "mad_header_decode had an error: %s",
mad_stream_errorstr (&mad->stream));
}
}
GST_LOG_OBJECT (mad, "parsing and decoding one frame now");
if (mad_frame_decode (&mad->frame, &mad->stream) == -1) {
GST_LOG_OBJECT (mad, "got error %d", mad->stream.error);
/* not enough data, need to wait for next buffer? */
if (mad->stream.error == MAD_ERROR_BUFLEN) {
if (mad->stream.next_frame == data) {
GST_LOG_OBJECT (mad,
"not enough data in tempbuffer (%d), breaking to get more",
size);
break;
} else {
GST_LOG_OBJECT (mad, "sync error, flushing unneeded data");
goto flush;
}
} else if (mad->stream.error == MAD_ERROR_BADDATAPTR) {
/* Flush data */
goto flush;
} else {
GST_WARNING_OBJECT (mad, "mad_frame_decode had an error: %s",
mad_stream_errorstr (&mad->stream));
if (!MAD_RECOVERABLE (mad->stream.error)) {
/* well, all may be well enough bytes later on ... */
GST_AUDIO_DECODER_ERROR (mad, 1, STREAM, DECODE, (NULL),
("mad error: %s", mad_stream_errorstr (&mad->stream)), ret);
/* so make sure we really move along ... */
if (!offset)
offset++;
goto exit;
} else {
const guint8 *before_sync, *after_sync;
mad_frame_mute (&mad->frame);
mad_synth_mute (&mad->synth);
before_sync = mad->stream.ptr.byte;
if (mad_stream_sync (&mad->stream) != 0)
GST_WARNING_OBJECT (mad, "mad_stream_sync failed");
after_sync = mad->stream.ptr.byte;
/* a succesful resync should make us drop bytes as consumed, so
* calculate from the byte pointers before and after resync */
consumed = after_sync - before_sync;
GST_DEBUG_OBJECT (mad, "resynchronization consumes %d bytes",
consumed);
GST_DEBUG_OBJECT (mad, "synced to data: 0x%0x 0x%0x",
*mad->stream.ptr.byte, *(mad->stream.ptr.byte + 1));
mad_stream_sync (&mad->stream);
/* recoverable errors pass */
goto flush;
}
}
} else if (mad->stream.error == MAD_ERROR_LOSTSYNC) {
GST_LOG_OBJECT (mad, "lost sync");
continue;
} else {
/* decoding ok; found frame */
ret = GST_FLOW_OK;
/* probably some bogus header, basically also lost sync */
GST_DEBUG_OBJECT (mad, "mad_header_decode had an error: %s",
mad_stream_errorstr (&mad->stream));
continue;
}
flush:
if (consumed == 0) {
consumed = mad->stream.next_frame - (data + offset);
g_assert (consumed >= 0);
}
if (ret == GST_FLOW_OK)
goto exit;
offset += consumed;
}
/* could have a frame now, subsequent will confirm */
offset = mad->stream.this_frame - data;
size = mad->stream.next_frame - mad->stream.this_frame;
g_assert (size);
GST_LOG_OBJECT (mad, "parsing and decoding one frame now "
"(offset %d, size %d)", offset, size);
if (mad_frame_decode (&mad->frame, &mad->stream) == -1) {
GST_LOG_OBJECT (mad, "got error %d", mad->stream.error);
/* not enough data, need to wait for next buffer? */
if (mad->stream.error == MAD_ERROR_BUFLEN) {
/* not really expect this error at this stage anymore
* assume bogus frame and bad sync and move along a bit */
GST_WARNING_OBJECT (mad, "not enough data (unexpected), moving along");
offset++;
goto resume;
} else if (mad->stream.error == MAD_ERROR_BADDATAPTR) {
GST_DEBUG_OBJECT (mad, "bad data ptr, skipping presumed frame");
/* flush past presumed frame */
offset += size;
goto resume;
} else {
GST_WARNING_OBJECT (mad, "mad_frame_decode had an error: %s",
mad_stream_errorstr (&mad->stream));
if (!MAD_RECOVERABLE (mad->stream.error)) {
/* well, all may be well enough bytes later on ... */
GST_AUDIO_DECODER_ERROR (mad, 1, STREAM, DECODE, (NULL),
("mad error: %s", mad_stream_errorstr (&mad->stream)), ret);
}
/* move along and try again */
offset++;
goto resume;
}
g_assert_not_reached ();
}
/* so decoded ok, got a frame now */
ret = GST_FLOW_OK;
break;
}
exit:
*_offset = offset;
*len = consumed;
*len = size;
/* ensure that if we added some dummy guard bytes above, we don't claim
to have used them as they're unknown to the caller. */