static gboolean
gst_h264_parse_check_valid_frame (GstBaseParse * parse,
GstBaseParseFrame * frame, guint * framesize, gint * skipsize)
{
GstH264Parse *h264parse = GST_H264_PARSE (parse);
GstBuffer *buffer = frame->buffer;
gint sc_pos, nal_pos, next_sc_pos, next_nal_pos;
guint8 *data;
guint size;
gboolean drain;
/* expect at least 3 bytes startcode == sc, and 2 bytes NALU payload */
if (G_UNLIKELY (GST_BUFFER_SIZE (buffer) < 5))
return FALSE;
/* need to configure aggregation */
if (G_UNLIKELY (h264parse->format == GST_H264_PARSE_FORMAT_NONE))
gst_h264_parse_negotiate (h264parse);
data = GST_BUFFER_DATA (buffer);
size = GST_BUFFER_SIZE (buffer);
GST_LOG_OBJECT (h264parse, "last_nal_pos: %d, last_scan_pos %d",
h264parse->last_nal_pos, h264parse->next_sc_pos);
nal_pos = h264parse->last_nal_pos;
next_sc_pos = h264parse->next_sc_pos;
if (!next_sc_pos) {
sc_pos = gst_h264_parse_find_sc (buffer, 0);
if (sc_pos == -1) {
/* SC not found, need more data */
sc_pos = GST_BUFFER_SIZE (buffer) - 3;
goto more;
}
nal_pos = sc_pos + 3;
next_sc_pos = nal_pos;
/* sc might have 2 or 3 0-bytes */
if (sc_pos > 0 && data[sc_pos - 1] == 00)
sc_pos--;
GST_LOG_OBJECT (h264parse, "found sc at offset %d", sc_pos);
} else {
/* previous checks already arrange sc at start */
sc_pos = 0;
}
drain = GST_BASE_PARSE_FRAME_DRAIN (frame);
while (TRUE) {
gint prev_sc_pos;
next_sc_pos = gst_h264_parse_find_sc (buffer, next_sc_pos);
if (next_sc_pos == -1) {
GST_LOG_OBJECT (h264parse, "no next sc");
if (drain) {
/* FLUSH/EOS, it's okay if we can't find the next frame */
next_sc_pos = size;
next_nal_pos = size;
} else {
next_sc_pos = size - 3;
goto more;
}
} else {
next_nal_pos = next_sc_pos + 3;
if (data[next_sc_pos - 1] == 00)
next_sc_pos--;
GST_LOG_OBJECT (h264parse, "found next sc at offset %d", next_sc_pos);
/* need at least 1 more byte of next NAL */
if (!drain && (next_nal_pos == size - 1))
goto more;
}
/* determine nal's sc position */
prev_sc_pos = nal_pos - 3;
g_assert (prev_sc_pos >= 0);
if (prev_sc_pos > 0 && data[prev_sc_pos - 1] == 0)
prev_sc_pos--;
/* already consume and gather info from NAL */
gst_h264_parse_process_nal (h264parse, data, prev_sc_pos, nal_pos,
next_sc_pos - nal_pos);
if (next_nal_pos >= size - 1 ||
gst_h264_parse_collect_nal (h264parse, data + nal_pos,
data + next_nal_pos))
break;
/* move along */
next_sc_pos = nal_pos = next_nal_pos;
}
*skipsize = sc_pos;
*framesize = next_sc_pos - sc_pos;
return TRUE;
more:
/* Ask for 1024 bytes more - this is an arbitrary choice */
gst_base_parse_set_min_frame_size (parse, GST_BUFFER_SIZE (buffer) + 1024);
/* skip up to initial startcode */
*skipsize = sc_pos;
/* resume scanning here next time */
h264parse->last_nal_pos = nal_pos;
h264parse->next_sc_pos = next_sc_pos;
return FALSE;
}
static gboolean
gst_h264_parse_check_valid_frame (GstBaseParse * parse,
GstBaseParseFrame * frame, guint * framesize, gint * skipsize)
{
GstH264Parse *h264parse = GST_H264_PARSE (parse);
GstBuffer *buffer = frame->buffer;
gint sc_pos, nal_pos, next_sc_pos, next_nal_pos;
guint8 *data;
guint size;
gboolean drain;
/* expect at least 3 bytes startcode == sc, and 2 bytes NALU payload */
if (G_UNLIKELY (GST_BUFFER_SIZE (buffer) < 5))
return FALSE;
/* need to configure aggregation */
if (G_UNLIKELY (h264parse->format == GST_H264_PARSE_FORMAT_NONE))
gst_h264_parse_negotiate (h264parse);
/* avoid stale cached parsing state */
if (!(frame->flags & GST_BASE_PARSE_FRAME_FLAG_PARSING)) {
GST_LOG_OBJECT (h264parse, "parsing new frame");
gst_h264_parse_reset_frame (h264parse);
frame->flags |= GST_BASE_PARSE_FRAME_FLAG_PARSING;
} else {
GST_LOG_OBJECT (h264parse, "resuming frame parsing");
}
data = GST_BUFFER_DATA (buffer);
size = GST_BUFFER_SIZE (buffer);
GST_LOG_OBJECT (h264parse, "last_nal_pos: %d, last_scan_pos %d",
h264parse->last_nal_pos, h264parse->next_sc_pos);
nal_pos = h264parse->last_nal_pos;
next_sc_pos = h264parse->next_sc_pos;
if (!next_sc_pos) {
sc_pos = gst_h264_parse_find_sc (buffer, 0);
if (sc_pos == -1) {
/* SC not found, need more data */
sc_pos = GST_BUFFER_SIZE (buffer) - 3;
/* avoid going < 0 later on */
nal_pos = next_sc_pos = sc_pos;
goto more;
}
nal_pos = sc_pos + 3;
next_sc_pos = nal_pos;
/* sc might have 2 or 3 0-bytes */
if (sc_pos > 0 && data[sc_pos - 1] == 00)
sc_pos--;
GST_LOG_OBJECT (h264parse, "found sc at offset %d", sc_pos);
} else {
/* previous checks already arrange sc at start */
sc_pos = 0;
}
drain = GST_BASE_PARSE_DRAINING (parse);
while (TRUE) {
gint prev_sc_pos;
next_sc_pos = gst_h264_parse_find_sc (buffer, next_sc_pos);
if (next_sc_pos == -1) {
GST_LOG_OBJECT (h264parse, "no next sc");
if (drain) {
/* FLUSH/EOS, it's okay if we can't find the next frame */
next_sc_pos = size;
next_nal_pos = size;
} else {
next_sc_pos = size - 3;
goto more;
}
} else {
next_nal_pos = next_sc_pos + 3;
if (data[next_sc_pos - 1] == 00)
next_sc_pos--;
GST_LOG_OBJECT (h264parse, "found next sc at offset %d", next_sc_pos);
/* need at least 1 more byte of next NAL */
if (!drain && (next_nal_pos == size - 1))
goto more;
}
/* determine nal's sc position */
prev_sc_pos = nal_pos - 3;
g_assert (prev_sc_pos >= 0);
if (prev_sc_pos > 0 && data[prev_sc_pos - 1] == 0)
prev_sc_pos--;
/* already consume and gather info from NAL */
if (G_UNLIKELY (next_sc_pos - nal_pos < 2)) {
GST_WARNING_OBJECT (h264parse, "input stream is corrupt; "
"it contains a NAL unit of length %d", next_sc_pos - nal_pos);
/* broken nal at start -> arrange to skip it,
* otherwise have it terminate current au
* (and so it will be skippd on next frame round) */
if (prev_sc_pos == sc_pos) {
*skipsize = sc_pos + 2;
return FALSE;
} else {
next_sc_pos = prev_sc_pos;
break;
}
}
gst_h264_parse_process_nal (h264parse, data, prev_sc_pos, nal_pos,
next_sc_pos - nal_pos);
if (next_nal_pos >= size - 1 ||
gst_h264_parse_collect_nal (h264parse, data + nal_pos,
data + next_nal_pos))
break;
/* move along */
next_sc_pos = nal_pos = next_nal_pos;
}
*skipsize = sc_pos;
*framesize = next_sc_pos - sc_pos;
return TRUE;
more:
/* ask for best next available */
*framesize = G_MAXUINT;
/* skip up to initial startcode */
*skipsize = sc_pos;
/* resume scanning here next time */
h264parse->last_nal_pos = nal_pos - sc_pos;
h264parse->next_sc_pos = next_sc_pos - sc_pos;
return FALSE;
}
