static GstFlowReturn
gst_ac3_parse_pre_push_frame (GstBaseParse * parse, GstBaseParseFrame * frame)
{
GstAc3Parse *ac3parse = GST_AC3_PARSE (parse);
if (!ac3parse->sent_codec_tag) {
GstTagList *taglist;
GstCaps *caps;
/* codec tag */
caps = gst_pad_get_current_caps (GST_BASE_PARSE_SRC_PAD (parse));
if (G_UNLIKELY (caps == NULL)) {
if (GST_PAD_IS_FLUSHING (GST_BASE_PARSE_SRC_PAD (parse))) {
GST_INFO_OBJECT (parse, "Src pad is flushing");
return GST_FLOW_FLUSHING;
} else {
GST_INFO_OBJECT (parse, "Src pad is not negotiated!");
return GST_FLOW_NOT_NEGOTIATED;
}
}
taglist = gst_tag_list_new_empty ();
gst_pb_utils_add_codec_description_to_tag_list (taglist,
GST_TAG_AUDIO_CODEC, caps);
gst_caps_unref (caps);
gst_base_parse_merge_tags (parse, taglist, GST_TAG_MERGE_REPLACE);
gst_tag_list_unref (taglist);
/* also signals the end of first-frame processing */
ac3parse->sent_codec_tag = TRUE;
}
return GST_FLOW_OK;
}
static gboolean
gst_ac3_parse_src_event (GstBaseParse * parse, GstEvent * event)
{
GstAc3Parse *ac3parse = GST_AC3_PARSE (parse);
if (G_UNLIKELY (GST_EVENT_TYPE (event) == GST_EVENT_CUSTOM_UPSTREAM) &&
gst_event_has_name (event, "ac3parse-set-alignment")) {
const GstStructure *st = gst_event_get_structure (event);
const gchar *align = gst_structure_get_string (st, "alignment");
if (g_str_equal (align, "iec61937")) {
GST_DEBUG_OBJECT (ac3parse, "Switching to iec61937 alignment");
g_atomic_int_set (&ac3parse->align, GST_AC3_PARSE_ALIGN_IEC61937);
} else if (g_str_equal (align, "frame")) {
GST_DEBUG_OBJECT (ac3parse, "Switching to frame alignment");
g_atomic_int_set (&ac3parse->align, GST_AC3_PARSE_ALIGN_FRAME);
} else {
g_atomic_int_set (&ac3parse->align, GST_AC3_PARSE_ALIGN_FRAME);
GST_WARNING_OBJECT (ac3parse, "Got unknown alignment request (%s) "
"reverting to frame alignment.",
gst_structure_get_string (st, "alignment"));
}
gst_event_unref (event);
return TRUE;
}
return GST_BASE_PARSE_CLASS (parent_class)->src_event (parse, event);
}
static gboolean
gst_ac3_parse_start (GstBaseParse * parse)
{
GstAc3Parse *ac3parse = GST_AC3_PARSE (parse);
GST_DEBUG_OBJECT (parse, "starting");
gst_ac3_parse_reset (ac3parse);
return TRUE;
}
static gboolean
gst_ac3_parse_set_sink_caps (GstBaseParse * parse, GstCaps * caps)
{
GstStructure *s;
GstAc3Parse *ac3parse = GST_AC3_PARSE (parse);
s = gst_caps_get_structure (caps, 0);
if (gst_structure_has_name (s, "audio/x-private1-ac3")) {
gst_pad_set_chain_function (parse->sinkpad, gst_ac3_parse_chain_priv);
} else {
gst_pad_set_chain_function (parse->sinkpad, ac3parse->baseparse_chainfunc);
}
return TRUE;
}
static GstFlowReturn
gst_ac3_parse_chain_priv (GstPad * pad, GstObject * parent, GstBuffer * buf)
{
GstAc3Parse *ac3parse = GST_AC3_PARSE (parent);
GstFlowReturn ret;
gsize size;
guint8 data[2];
gint offset;
gint len;
GstBuffer *subbuf;
gint first_access;
size = gst_buffer_get_size (buf);
if (size < 2)
goto not_enough_data;
gst_buffer_extract (buf, 0, data, 2);
first_access = (data[0] << 8) | data[1];
/* Skip the first_access header */
offset = 2;
if (first_access > 1) {
/* Length of data before first_access */
len = first_access - 1;
if (len <= 0 || offset + len > size)
goto bad_first_access_parameter;
subbuf = gst_buffer_copy_region (buf, GST_BUFFER_COPY_ALL, offset, len);
GST_BUFFER_DTS (subbuf) = GST_CLOCK_TIME_NONE;
GST_BUFFER_PTS (subbuf) = GST_CLOCK_TIME_NONE;
ret = ac3parse->baseparse_chainfunc (pad, parent, subbuf);
if (ret != GST_FLOW_OK && ret != GST_FLOW_NOT_LINKED) {
gst_buffer_unref (buf);
goto done;
}
offset += len;
len = size - offset;
if (len > 0) {
subbuf = gst_buffer_copy_region (buf, GST_BUFFER_COPY_ALL, offset, len);
GST_BUFFER_PTS (subbuf) = GST_BUFFER_PTS (buf);
GST_BUFFER_DTS (subbuf) = GST_BUFFER_DTS (buf);
ret = ac3parse->baseparse_chainfunc (pad, parent, subbuf);
}
gst_buffer_unref (buf);
} else {
/* first_access = 0 or 1, so if there's a timestamp it applies to the first byte */
subbuf =
gst_buffer_copy_region (buf, GST_BUFFER_COPY_ALL, offset,
size - offset);
GST_BUFFER_PTS (subbuf) = GST_BUFFER_PTS (buf);
GST_BUFFER_DTS (subbuf) = GST_BUFFER_DTS (buf);
gst_buffer_unref (buf);
ret = ac3parse->baseparse_chainfunc (pad, parent, subbuf);
}
done:
return ret;
/* ERRORS */
not_enough_data:
{
GST_ELEMENT_ERROR (GST_ELEMENT (ac3parse), STREAM, FORMAT, (NULL),
("Insufficient data in buffer. Can't determine first_acess"));
gst_buffer_unref (buf);
return GST_FLOW_ERROR;
}
bad_first_access_parameter:
{
GST_ELEMENT_ERROR (GST_ELEMENT (ac3parse), STREAM, FORMAT, (NULL),
("Bad first_access parameter (%d) in buffer", first_access));
gst_buffer_unref (buf);
return GST_FLOW_ERROR;
}
}
static GstFlowReturn
gst_ac3_parse_handle_frame (GstBaseParse * parse,
GstBaseParseFrame * frame, gint * skipsize)
{
GstAc3Parse *ac3parse = GST_AC3_PARSE (parse);
GstBuffer *buf = frame->buffer;
GstByteReader reader;
gint off;
gboolean lost_sync, draining, eac, more = FALSE;
guint frmsiz, blocks, sid;
guint rate, chans;
gboolean update_rate = FALSE;
gint framesize = 0;
gint have_blocks = 0;
GstMapInfo map;
gboolean ret = FALSE;
GstFlowReturn res = GST_FLOW_OK;
gst_buffer_map (buf, &map, GST_MAP_READ);
if (G_UNLIKELY (map.size < 8)) {
*skipsize = 1;
goto cleanup;
}
gst_byte_reader_init (&reader, map.data, map.size);
off = gst_byte_reader_masked_scan_uint32 (&reader, 0xffff0000, 0x0b770000,
0, map.size);
GST_LOG_OBJECT (parse, "possible sync at buffer offset %d", off);
/* didn't find anything that looks like a sync word, skip */
if (off < 0) {
*skipsize = map.size - 3;
goto cleanup;
}
/* possible frame header, but not at offset 0? skip bytes before sync */
if (off > 0) {
*skipsize = off;
goto cleanup;
}
/* make sure the values in the frame header look sane */
if (!gst_ac3_parse_frame_header (ac3parse, buf, 0, &frmsiz, &rate, &chans,
&blocks, &sid, &eac)) {
*skipsize = off + 2;
goto cleanup;
}
GST_LOG_OBJECT (parse, "size: %u, blocks: %u, rate: %u, chans: %u", frmsiz,
blocks, rate, chans);
framesize = frmsiz;
if (G_UNLIKELY (g_atomic_int_get (&ac3parse->align) ==
GST_AC3_PARSE_ALIGN_NONE))
gst_ac3_parse_set_alignment (ac3parse, eac);
GST_LOG_OBJECT (parse, "got frame");
lost_sync = GST_BASE_PARSE_LOST_SYNC (parse);
draining = GST_BASE_PARSE_DRAINING (parse);
if (g_atomic_int_get (&ac3parse->align) == GST_AC3_PARSE_ALIGN_IEC61937) {
/* We need 6 audio blocks from each substream, so we keep going forwards
* till we have it */
g_assert (blocks > 0);
GST_LOG_OBJECT (ac3parse, "Need %d frames before pushing", 6 / blocks);
if (sid != 0) {
/* We need the first substream to be the one with id 0 */
GST_LOG_OBJECT (ac3parse, "Skipping till we find sid 0");
*skipsize = off + 2;
goto cleanup;
}
framesize = 0;
/* Loop till we have 6 blocks per substream */
for (have_blocks = 0; !more && have_blocks < 6; have_blocks += blocks) {
/* Loop till we get one frame from each substream */
do {
framesize += frmsiz;
if (!gst_byte_reader_skip (&reader, frmsiz)
|| map.size < (framesize + 6)) {
more = TRUE;
break;
}
if (!gst_ac3_parse_frame_header (ac3parse, buf, framesize, &frmsiz,
NULL, NULL, NULL, &sid, &eac)) {
*skipsize = off + 2;
goto cleanup;
}
} while (sid);
}
/* We're now at the next frame, so no need to skip if resyncing */
frmsiz = 0;
}
if (lost_sync && !draining) {
guint16 word = 0;
GST_DEBUG_OBJECT (ac3parse, "resyncing; checking next frame syncword");
if (more || !gst_byte_reader_skip (&reader, frmsiz) ||
!gst_byte_reader_get_uint16_be (&reader, &word)) {
GST_DEBUG_OBJECT (ac3parse, "... but not sufficient data");
gst_base_parse_set_min_frame_size (parse, framesize + 8);
*skipsize = 0;
goto cleanup;
} else {
if (word != 0x0b77) {
GST_DEBUG_OBJECT (ac3parse, "0x%x not OK", word);
*skipsize = off + 2;
goto cleanup;
} else {
/* ok, got sync now, let's assume constant frame size */
gst_base_parse_set_min_frame_size (parse, framesize);
}
}
}
/* expect to have found a frame here */
g_assert (framesize);
ret = TRUE;
/* arrange for metadata setup */
if (G_UNLIKELY (sid)) {
/* dependent frame, no need to (ac)count for or consider further */
GST_LOG_OBJECT (parse, "sid: %d", sid);
frame->flags |= GST_BASE_PARSE_FRAME_FLAG_NO_FRAME;
/* TODO maybe also mark as DELTA_UNIT,
* if that does not surprise baseparse elsewhere */
/* occupies same time space as previous base frame */
if (G_LIKELY (GST_BUFFER_TIMESTAMP (buf) >= GST_BUFFER_DURATION (buf)))
GST_BUFFER_TIMESTAMP (buf) -= GST_BUFFER_DURATION (buf);
/* only shortcut if we already arranged for caps */
if (G_LIKELY (ac3parse->sample_rate > 0))
goto cleanup;
}
if (G_UNLIKELY (ac3parse->sample_rate != rate || ac3parse->channels != chans
|| ac3parse->eac != eac)) {
GstCaps *caps = gst_caps_new_simple (eac ? "audio/x-eac3" : "audio/x-ac3",
"framed", G_TYPE_BOOLEAN, TRUE, "rate", G_TYPE_INT, rate,
"channels", G_TYPE_INT, chans, NULL);
gst_caps_set_simple (caps, "alignment", G_TYPE_STRING,
g_atomic_int_get (&ac3parse->align) == GST_AC3_PARSE_ALIGN_IEC61937 ?
"iec61937" : "frame", NULL);
gst_pad_set_caps (GST_BASE_PARSE_SRC_PAD (parse), caps);
gst_caps_unref (caps);
ac3parse->sample_rate = rate;
ac3parse->channels = chans;
ac3parse->eac = eac;
update_rate = TRUE;
}
if (G_UNLIKELY (ac3parse->blocks != blocks)) {
ac3parse->blocks = blocks;
update_rate = TRUE;
}
if (G_UNLIKELY (update_rate))
gst_base_parse_set_frame_rate (parse, rate, 256 * blocks, 2, 2);
cleanup:
gst_buffer_unmap (buf, &map);
if (ret && framesize <= map.size) {
res = gst_base_parse_finish_frame (parse, frame, framesize);
}
return res;
}
static GstFlowReturn
gst_ac3_parse_parse_frame (GstBaseParse * parse, GstBaseParseFrame * frame)
{
GstAc3Parse *ac3parse = GST_AC3_PARSE (parse);
GstBuffer *buf = frame->buffer;
guint fsize, rate, chans, blocks, sid;
gboolean eac, update_rate = FALSE;
if (!gst_ac3_parse_frame_header (ac3parse, buf, 0, &fsize, &rate, &chans,
&blocks, &sid, &eac))
goto broken_header;
GST_LOG_OBJECT (parse, "size: %u, blocks: %u, rate: %u, chans: %u", fsize,
blocks, rate, chans);
if (G_UNLIKELY (sid)) {
/* dependent frame, no need to (ac)count for or consider further */
GST_LOG_OBJECT (parse, "sid: %d", sid);
frame->flags |= GST_BASE_PARSE_FRAME_FLAG_NO_FRAME;
/* TODO maybe also mark as DELTA_UNIT,
* if that does not surprise baseparse elsewhere */
/* occupies same time space as previous base frame */
if (G_LIKELY (GST_BUFFER_TIMESTAMP (buf) >= GST_BUFFER_DURATION (buf)))
GST_BUFFER_TIMESTAMP (buf) -= GST_BUFFER_DURATION (buf);
/* only return if we already arranged for caps */
if (G_LIKELY (ac3parse->sample_rate > 0))
return GST_FLOW_OK;
}
if (G_UNLIKELY (ac3parse->sample_rate != rate || ac3parse->channels != chans
|| ac3parse->eac != eac)) {
GstCaps *caps = gst_caps_new_simple (eac ? "audio/x-eac3" : "audio/x-ac3",
"framed", G_TYPE_BOOLEAN, TRUE, "rate", G_TYPE_INT, rate,
"channels", G_TYPE_INT, chans, NULL);
gst_caps_set_simple (caps, "alignment", G_TYPE_STRING,
g_atomic_int_get (&ac3parse->align) == GST_AC3_PARSE_ALIGN_IEC61937 ?
"iec61937" : "frame", NULL);
gst_buffer_set_caps (buf, caps);
gst_pad_set_caps (GST_BASE_PARSE_SRC_PAD (parse), caps);
gst_caps_unref (caps);
ac3parse->sample_rate = rate;
ac3parse->channels = chans;
ac3parse->eac = eac;
update_rate = TRUE;
}
if (G_UNLIKELY (ac3parse->blocks != blocks)) {
ac3parse->blocks = blocks;
update_rate = TRUE;
}
if (G_UNLIKELY (update_rate))
gst_base_parse_set_frame_rate (parse, rate, 256 * blocks, 2, 2);
return GST_FLOW_OK;
/* ERRORS */
broken_header:
{
/* this really shouldn't ever happen */
GST_ELEMENT_ERROR (parse, STREAM, DECODE, (NULL), (NULL));
return GST_FLOW_ERROR;
}
}
static gboolean
gst_ac3_parse_check_valid_frame (GstBaseParse * parse,
GstBaseParseFrame * frame, guint * framesize, gint * skipsize)
{
GstAc3Parse *ac3parse = GST_AC3_PARSE (parse);
GstBuffer *buf = frame->buffer;
GstByteReader reader = GST_BYTE_READER_INIT_FROM_BUFFER (buf);
gint off;
gboolean lost_sync, draining, eac, more = FALSE;
guint frmsiz, blocks, sid;
gint have_blocks = 0;
if (G_UNLIKELY (GST_BUFFER_SIZE (buf) < 6))
return FALSE;
off = gst_byte_reader_masked_scan_uint32 (&reader, 0xffff0000, 0x0b770000,
0, GST_BUFFER_SIZE (buf));
GST_LOG_OBJECT (parse, "possible sync at buffer offset %d", off);
/* didn't find anything that looks like a sync word, skip */
if (off < 0) {
*skipsize = GST_BUFFER_SIZE (buf) - 3;
return FALSE;
}
/* possible frame header, but not at offset 0? skip bytes before sync */
if (off > 0) {
*skipsize = off;
return FALSE;
}
/* make sure the values in the frame header look sane */
if (!gst_ac3_parse_frame_header (ac3parse, buf, 0, &frmsiz, NULL, NULL,
&blocks, &sid, &eac)) {
*skipsize = off + 2;
return FALSE;
}
*framesize = frmsiz;
if (G_UNLIKELY (g_atomic_int_get (&ac3parse->align) ==
GST_AC3_PARSE_ALIGN_NONE))
gst_ac3_parse_set_alignment (ac3parse, eac);
GST_LOG_OBJECT (parse, "got frame");
lost_sync = GST_BASE_PARSE_LOST_SYNC (parse);
draining = GST_BASE_PARSE_DRAINING (parse);
if (g_atomic_int_get (&ac3parse->align) == GST_AC3_PARSE_ALIGN_IEC61937) {
/* We need 6 audio blocks from each substream, so we keep going forwards
* till we have it */
g_assert (blocks > 0);
GST_LOG_OBJECT (ac3parse, "Need %d frames before pushing", 6 / blocks);
if (sid != 0) {
/* We need the first substream to be the one with id 0 */
GST_LOG_OBJECT (ac3parse, "Skipping till we find sid 0");
*skipsize = off + 2;
return FALSE;
}
*framesize = 0;
/* Loop till we have 6 blocks per substream */
for (have_blocks = 0; !more && have_blocks < 6; have_blocks += blocks) {
/* Loop till we get one frame from each substream */
do {
*framesize += frmsiz;
if (!gst_byte_reader_skip (&reader, frmsiz) ||
GST_BUFFER_SIZE (buf) < (*framesize + 6)) {
more = TRUE;
break;
}
if (!gst_ac3_parse_frame_header (ac3parse, buf, *framesize, &frmsiz,
NULL, NULL, NULL, &sid, &eac)) {
*skipsize = off + 2;
return FALSE;
}
} while (sid);
}
/* We're now at the next frame, so no need to skip if resyncing */
frmsiz = 0;
}
if (lost_sync && !draining) {
guint16 word = 0;
GST_DEBUG_OBJECT (ac3parse, "resyncing; checking next frame syncword");
if (more || !gst_byte_reader_skip (&reader, frmsiz) ||
!gst_byte_reader_get_uint16_be (&reader, &word)) {
GST_DEBUG_OBJECT (ac3parse, "... but not sufficient data");
gst_base_parse_set_min_frame_size (parse, *framesize + 6);
*skipsize = 0;
return FALSE;
} else {
if (word != 0x0b77) {
GST_DEBUG_OBJECT (ac3parse, "0x%x not OK", word);
*skipsize = off + 2;
return FALSE;
} else {
/* ok, got sync now, let's assume constant frame size */
gst_base_parse_set_min_frame_size (parse, *framesize);
}
}
}
return TRUE;
}
