diff options
| -rw-r--r-- | ChangeLog | 11 | ||||
| -rw-r--r-- | gst/rtp/gstrtpmp4gdepay.c | 152 |
2 files changed, 142 insertions, 21 deletions
@@ -1,3 +1,14 @@ +2008-09-15 Wim Taymans <wim.taymans@collabora.co.uk> + + * gst/rtp/gstrtpmp4gdepay.c: (gst_bs_parse_init), + (gst_bs_parse_read), (gst_rtp_mp4g_depay_process): + Change some of the ranges in the caps, mostly for the amount of bits we + can use. + Added a little bitstream parse and use it to parse the AU header fields. + Check for malformed and wrongly sized packets better. + Implement more header field parsing. + Handle the size of fragmented packets correctly. + 2008-09-14 Edward Hervey <edward.hervey@collabora.co.uk> Patch by: Jonathan Matthew <notverysmart@gmail.com> diff --git a/gst/rtp/gstrtpmp4gdepay.c b/gst/rtp/gstrtpmp4gdepay.c index 35122656..d5942440 100644 --- a/gst/rtp/gstrtpmp4gdepay.c +++ b/gst/rtp/gstrtpmp4gdepay.c @@ -67,16 +67,71 @@ GST_STATIC_PAD_TEMPLATE ("sink", /* "maxdisplacement = (string) [1,MAX], " */ /* "de-interleavebuffersize = (string) [1,MAX], " */ /* Optional configuration parameters */ - /* "sizelength = (string) [1, 16], " *//* max 16 bits, should be enough... */ - /* "indexlength = (string) [1, 8], " */ - /* "indexdeltalength = (string) [1, 8], " */ - /* "ctsdeltalength = (string) [1, 64], " */ - /* "dtsdeltalength = (string) [1, 64], " */ + /* "sizelength = (string) [1, 32], " */ + /* "indexlength = (string) [1, 32], " */ + /* "indexdeltalength = (string) [1, 32], " */ + /* "ctsdeltalength = (string) [1, 32], " */ + /* "dtsdeltalength = (string) [1, 32], " */ /* "randomaccessindication = (string) {0, 1}, " */ - /* "streamstateindication = (string) [0, 64], " */ - /* "auxiliarydatasizelength = (string) [0, 64]" */ ) + /* "streamstateindication = (string) [0, 32], " */ + /* "auxiliarydatasizelength = (string) [0, 32]" */ ) ); +/* simple bitstream parser */ +typedef struct +{ + const guint8 *data; + const guint8 *end; + gint head; /* bitpos in the cache of next bit */ + guint64 cache; /* cached bytes */ +} GstBsParse; + +static void +gst_bs_parse_init (GstBsParse * bs, const guint8 * data, guint size) +{ + bs->data = data; + bs->end = data + size; + bs->head = 0; + bs->cache = 0xffffffff; +} + +static guint32 +gst_bs_parse_read (GstBsParse * bs, guint n) +{ + guint32 res = 0; + gint shift; + + if (n == 0) + return res; + + /* fill up the cache if we need to */ + while (bs->head < n) { + if (bs->data >= bs->end) { + /* we're at the end, can't produce more than head number of bits */ + n = bs->head; + break; + } + /* shift bytes in cache, moving the head bits of the cache left */ + bs->cache = (bs->cache << 8) | *bs->data++; + bs->head += 8; + } + + /* bring the required bits down and truncate */ + if ((shift = bs->head - n) > 0) + res = bs->cache >> shift; + else + res = bs->cache; + + /* mask out required bits */ + if (n < 32) + res &= (1 << n) - 1; + + bs->head = shift; + + return res; +} + + GST_BOILERPLATE (GstRtpMP4GDepay, gst_rtp_mp4g_depay, GstBaseRTPDepayload, GST_TYPE_BASE_RTP_DEPAYLOAD); @@ -261,22 +316,25 @@ gst_rtp_mp4g_depay_process (GstBaseRTPDepayload * depayload, GstBuffer * buf) } { - gint payload_len, payload_header; + gint payload_len, payload_AU; guint8 *payload; guint32 timestamp; guint AU_headers_len; - guint AU_size, AU_index; + guint AU_size, AU_index, payload_AU_size; gboolean M; payload_len = gst_rtp_buffer_get_payload_len (buf); payload = gst_rtp_buffer_get_payload (buf); - payload_header = 0; timestamp = gst_rtp_buffer_get_timestamp (buf); M = gst_rtp_buffer_get_marker (buf); if (rtpmp4gdepay->sizelength > 0) { gint num_AU_headers, AU_headers_bytes, i; + GstBsParse bs; + + if (payload_len < 2) + goto short_payload; /* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- .. -+-+-+-+-+-+-+-+-+-+ * |AU-headers-length|AU-header|AU-header| |AU-header|padding| @@ -295,22 +353,67 @@ gst_rtp_mp4g_depay_process (GstBaseRTPDepayload * depayload, GstBuffer * buf) /* skip header */ payload += 2; - /* skip special headers */ - payload_header = 2 + AU_headers_bytes; + payload_len -= 2; + + if (payload_len < AU_headers_bytes) + goto short_payload; + + /* skip special headers, point to first payload AU */ + payload_AU = 2 + AU_headers_bytes; + payload_AU_size = payload_len - AU_headers_bytes; + + /* point the bitstream parser to the first AU header bit */ + gst_bs_parse_init (&bs, payload, payload_len); + + for (i = 0; i < num_AU_headers && payload_AU_size > 0; i++) { + /* parse AU header + * +---------------------------------------+ + * | AU-size | + * +---------------------------------------+ + * | AU-Index / AU-Index-delta | + * +---------------------------------------+ + * | CTS-flag | + * +---------------------------------------+ + * | CTS-delta | + * +---------------------------------------+ + * | DTS-flag | + * +---------------------------------------+ + * | DTS-delta | + * +---------------------------------------+ + * | RAP-flag | + * +---------------------------------------+ + * | Stream-state | + * +---------------------------------------+ + */ + AU_size = gst_bs_parse_read (&bs, rtpmp4gdepay->sizelength); + if (i == 0) + AU_index = gst_bs_parse_read (&bs, rtpmp4gdepay->indexlength); + else + AU_index = gst_bs_parse_read (&bs, rtpmp4gdepay->indexdeltalength); + if (rtpmp4gdepay->ctsdeltalength > 0) { + if (gst_bs_parse_read (&bs, 1)) + gst_bs_parse_read (&bs, rtpmp4gdepay->ctsdeltalength); + } + if (rtpmp4gdepay->dtsdeltalength > 0) { + if (gst_bs_parse_read (&bs, 1)) + gst_bs_parse_read (&bs, rtpmp4gdepay->dtsdeltalength); + } + if (rtpmp4gdepay->randomaccessindication) + gst_bs_parse_read (&bs, 1); + if (rtpmp4gdepay->streamstateindication > 0) + gst_bs_parse_read (&bs, rtpmp4gdepay->streamstateindication); - for (i = 0; i < num_AU_headers; i++) { - /* FIXME, use bits */ - AU_size = ((payload[0] << 8) | payload[1]) >> 3; - AU_index = payload[1] & 0x7; - payload += 2; + GST_DEBUG_OBJECT (rtpmp4gdepay, "size %d, index %d", AU_size, AU_index); - GST_DEBUG_OBJECT (rtpmp4gdepay, "len, %d, size %d, index %d", - AU_headers_len, AU_size, AU_index); + /* fragmented pakets have the AU_size set to the size of the + * unfragmented AU. */ + if (AU_size > payload_AU_size) + AU_size = payload_AU_size; /* collect stuff in the adapter, strip header from payload and push in * the adapter */ outbuf = - gst_rtp_buffer_get_payload_subbuffer (buf, payload_header, AU_size); + gst_rtp_buffer_get_payload_subbuffer (buf, payload_AU, AU_size); gst_adapter_push (rtpmp4gdepay->adapter, outbuf); if (M) { @@ -331,7 +434,8 @@ gst_rtp_mp4g_depay_process (GstBaseRTPDepayload * depayload, GstBuffer * buf) else gst_base_rtp_depayload_push (depayload, outbuf); } - payload_header += AU_size; + payload_AU += AU_size; + payload_AU_size -= AU_size; } } else { /* push complete buffer in adapter */ @@ -363,6 +467,12 @@ bad_packet: ("Packet did not validate."), (NULL)); return NULL; } +short_payload: + { + GST_ELEMENT_WARNING (rtpmp4gdepay, STREAM, DECODE, + ("Packet payload was too short."), (NULL)); + return NULL; + } } static GstStateChangeReturn |