From: David Flynn <dav...@rd.bbc.co.uk>
Traditionally, clients were required to wrap the decoder with a TLB,
that stored presentation time vs input picture number; when pulling
a picture, the presentation time would be extracted from the TLB.
Clients may be simplified by allowing schroedinger to do the tagging
based on simple rules:
- a buffer may be supplied with a tag and free function
- the tag is associated with the first byte of the buffer data
- when using the autoparse api, the tag becomes associated with
the next picture data unit to commence at or after the start of
the buffer.
- in cases where the above rule would associate multiple tags
with one picture, the oldest shall take precedence.
- tags are made avaliable as a member of the SchroFrame structure.
- the contents of the tag are transparent to the decoder.
Signed-off-by: David Flynn <dav...@rd.bbc.co.uk>
---
schroedinger/schrobuffer.c | 2 +
schroedinger/schrobuffer.h | 2 +
schroedinger/schrobufferlist.c | 63 ++++++++++++++++++++++++++++++++++-----
schroedinger/schrodecoder.c | 24 +++++++++++++++
schroedinger/schrodecoder.h | 9 ++++++
schroedinger/schroframe.h | 4 ++
6 files changed, 96 insertions(+), 8 deletions(-)
diff --git a/schroedinger/schrobuffer.c b/schroedinger/schrobuffer.c
index 3e1636a..a38916d 100644
--- a/schroedinger/schrobuffer.c
+++ b/schroedinger/schrobuffer.c
@@ -82,6 +82,8 @@ schro_buffer_unref (SchroBuffer * buffer)
SCHRO_DEBUG("free %p", buffer);
if (buffer->free)
buffer->free (buffer, buffer->priv);
+ if (buffer->tag_free)
+ buffer->tag_free (buffer->tag);
schro_free (buffer);
}
}
diff --git a/schroedinger/schrobuffer.h b/schroedinger/schrobuffer.h
index f3df89c..c822049 100644
--- a/schroedinger/schrobuffer.h
+++ b/schroedinger/schrobuffer.h
@@ -20,6 +20,8 @@ struct _SchroBuffer
void (*free) (SchroBuffer *, void *);
void *priv;
+ void (*tag_free) (void *); /* NB, must be able to handle tag_free(NULL) */
+ void *tag;
};
SchroBuffer *schro_buffer_new (void);
diff --git a/schroedinger/schrobufferlist.c b/schroedinger/schrobufferlist.c
index ae7e379..05a588b 100644
--- a/schroedinger/schrobufferlist.c
+++ b/schroedinger/schrobufferlist.c
@@ -232,8 +232,10 @@ schro_buflist_flush (SchroBufferList *buflist, unsigned
amount)
SchroBuffer *
schro_buflist_extract (SchroBufferList *buflist, unsigned start, unsigned len)
{
- SchroBuffer *buf;
- unsigned start_orig = start;
+ SchroBuffer *buf, *dst;
+ void *tag = NULL;
+ void (*tag_free) (void *) = NULL;
+ unsigned pos = start;
int bufidx;
uint8_t tmp;
@@ -249,19 +251,64 @@ schro_buflist_extract (SchroBufferList *buflist, unsigned
start, unsigned len)
}
/* guaranteed that the range is wholly contained within buflist */
- bufidx = schro_buflist_internal_seek(buflist, &start);
+ bufidx = schro_buflist_internal_seek(buflist, &pos);
SCHRO_ASSERT(bufidx < buflist->list->n);
buf = buflist->list->members[bufidx];
- if (start + len <= buf->length) {
+ /* Semantics for private void* in buffers in a bufferlist:
+ * - Shall be associated with the next dataunit to commence after (or at)
+ * the start of the buffer in the bufferist.
+ * - May only be extracted once.
+ * - If multiple void* could apply to the next dataunit, behaviour is
undefined
+ * NB: this implementation will discard all but the first.
+ * - Ownership of the tag is transfered to the output buffer
+ */
+ tag = buf->tag;
+ tag_free = buf->tag_free;
+ buf->tag = NULL;
+
+ if (pos + len <= buf->length) {
/* Special case, if the requested range is contained within a single
* buffer, then use a subbuffer */
- return schro_buffer_new_subbuffer (buf, start, len);
+ dst = schro_buffer_new_subbuffer (buf, pos, len);
+ dst->tag = tag;
+ dst->tag_free = tag_free;
+ return dst;
}
- buf = schro_buffer_new_and_alloc (len);
- schro_buflist_peekbytes (buf->data, len, buflist, start_orig);
+ /* dataunit spans multiple buffers */
+ dst = schro_buffer_new_and_alloc (len);
+ dst->tag = tag;
+ dst->tag_free = tag_free;
+ tag = NULL;
+ schro_buflist_peekbytes (dst->data, len, buflist, start);
+
+ /* sort out rescuing the first tag that was in the extracted
+ * region and saving it ready for extraction at start+len. */
+ len += pos;
+ for (pos = 0; pos < len;)
+ {
+ buf = buflist->list->members[bufidx];
+ if (!tag) {
+ /* find the first non null tag we come across, take it,
+ * and [2] store it in the last buffer read from */
+ tag = buf->tag;
+ buf->tag = NULL;
+ }
+ /* any intermediate tags are discarded */
+ if (buf->tag_free) {
+ buf->tag_free(buf->tag);
+ buf->tag = NULL;
+ }
+ pos += buf->length;
+ bufidx++;
+ }
+ /* [2] store in last buffer of buflist */
+ /* xxx, this may need to be moved to the next buffer if
+ * exact consumption of buf occurs */
+ buf->tag = tag;
+ buf->tag_free = tag_free;
- return buf;
+ return dst;
}
diff --git a/schroedinger/schrodecoder.c b/schroedinger/schrodecoder.c
index 66f8516..3f3fb38 100644
--- a/schroedinger/schrodecoder.c
+++ b/schroedinger/schrodecoder.c
@@ -653,6 +653,10 @@ schro_decoder_pull (SchroDecoder *decoder)
/* XXX would be nice to warn if expected picture not present */
frame = schro_frame_ref (picture->output_picture);
+ frame->tag = picture->tag;
+ frame->tag_free = picture->tag_free;
+ picture->tag = NULL;
+
schro_picture_unref (picture);
return frame;
@@ -1021,9 +1025,13 @@ schro_decoder_push (SchroDecoder *decoder, SchroBuffer
*buffer)
}
if (SCHRO_PARSE_CODE_IS_PICTURE(parse_code)) {
+ SchroDecoder *decoder = instance->decoder;
if (!instance->have_sequence_header) {
SCHRO_INFO ("no sequence header -- dropping picture");
+ if (decoder->free_picture_tag)
+ decoder->free_picture_tag(decoder->next_picture_tag);
+ decoder->next_picture_tag = NULL;
schro_buffer_unref (buffer);
return SCHRO_DECODER_OK;
}
@@ -1060,6 +1068,17 @@ schro_decoder_autoparse_push (SchroDecoder *decoder,
SchroBuffer *buffer)
if (!buffer)
return SCHRO_DECODER_NEED_BITS;
+ /* Buffers may have associated (tagged) private data.
+ * This data is to be associated with the next(/this) picture data unit */
+ if (buffer->tag) {
+ if (decoder->free_picture_tag) {
+ decoder->free_picture_tag (decoder->next_picture_tag);
+ }
+ decoder->next_picture_tag = buffer->tag;
+ decoder->free_picture_tag = buffer->tag_free;
+ }
+ buffer->tag_free = buffer->tag = NULL;
+
switch (schro_decoder_push (decoder, buffer)) {
default:
break;
@@ -1085,6 +1104,11 @@ schro_decoder_iterate_picture (SchroDecoderInstance
*instance, SchroBuffer *buff
picture->input_buffer = buffer;
+ picture->tag = decoder->next_picture_tag;
+ picture->tag_free = decoder->free_picture_tag;
+ decoder->free_picture_tag =
+ decoder->next_picture_tag = NULL;
+
params->num_refs = SCHRO_PARSE_CODE_NUM_REFS(parse_code);
params->is_lowdelay = SCHRO_PARSE_CODE_IS_LOW_DELAY(parse_code);
params->is_noarith = !SCHRO_PARSE_CODE_USING_AC(parse_code);
diff --git a/schroedinger/schrodecoder.h b/schroedinger/schrodecoder.h
index 8281efe..156ebae 100644
--- a/schroedinger/schrodecoder.h
+++ b/schroedinger/schrodecoder.h
@@ -52,6 +52,11 @@ struct _SchroDecoder {
SchroBufferList *input_buflist;
SchroParseSyncState *sps;
+ /* private data that is supplied with the input bitstream and
+ * is to be associated with the next picture to occur */
+ void *next_picture_tag;
+ void (*free_picture_tag) (void*);
+
SchroDecoderInstance *instance;
};
@@ -141,6 +146,10 @@ struct _SchroPicture {
int has_md5;
uint8_t md5_checksum[32];
+
+ /* private data that is associated with this picture */
+ void *tag;
+ void (*tag_free) (void*);
};
#endif
diff --git a/schroedinger/schroframe.h b/schroedinger/schroframe.h
index 4b0bb76..ac8516e 100644
--- a/schroedinger/schroframe.h
+++ b/schroedinger/schroframe.h
@@ -88,6 +88,10 @@ struct _SchroFrame {
void *virt_priv2;
int extension;
+
+ /* private data that is associated with this picture */
+ void *tag;
+ void (*tag_free) (void*);
};
struct _SchroUpsampledFrame {
--
1.5.6.5
------------------------------------------------------------------------------
This SF.net email is sponsored by:
SourcForge Community
SourceForge wants to tell your story.
http://p.sf.net/sfu/sf-spreadtheword
_______________________________________________
Schrodinger-devel mailing list
Schrodinger-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/schrodinger-devel
