gstreamer/gst/asfdemux/asfpacket.c

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/* GStreamer ASF/WMV/WMA demuxer
* Copyright (C) 2007 Tim-Philipp Müller <tim centricular net>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/* FIXME:
* file:///home/tpm/samples/video/asf//336370-regis-velo862.wmv
* file:///home/tpm/samples/video/asf//336370-eichhoer.wmv
* throw errors (not always necessarily) in this code path
* (looks like they carry broken payloads/packets though) */
#include "asfpacket.h"
#include <gst/gstutils.h>
#include <gst/gstinfo.h>
#include <string.h>
/* we are unlikely to deal with lengths > 2GB here any time soon, so just
* return a signed int and use that for error reporting */
static gint
asf_packet_read_varlen_int (guint lentype_flags, guint lentype_bit_offset,
const guint8 ** p_data, guint * p_size)
{
const guint lens[4] = { 0, 1, 2, 4 };
guint len, val;
len = lens[(lentype_flags >> lentype_bit_offset) & 0x03];
/* will make caller bail out with a short read if there's not enough data */
if (*p_size < len) {
GST_WARNING ("need %u bytes, but only %u bytes available", len, *p_size);
return -1;
}
switch (len) {
case 0:
val = 0;
break;
case 1:
val = GST_READ_UINT8 (*p_data);
break;
case 2:
val = GST_READ_UINT16_LE (*p_data);
break;
case 4:
val = GST_READ_UINT32_LE (*p_data);
break;
default:
g_assert_not_reached ();
}
*p_data += len;
*p_size -= len;
return (gint) val;
}
static GstBuffer *
asf_packet_create_payload_buffer (AsfPacket * packet, const guint8 ** p_data,
guint * p_size, guint payload_len)
{
guint off;
g_assert (payload_len <= *p_size);
off = (guint) (*p_data - GST_BUFFER_DATA (packet->buf));
g_assert (off < GST_BUFFER_SIZE (packet->buf));
*p_data += payload_len;
*p_size -= payload_len;
return gst_buffer_create_sub (packet->buf, off, payload_len);
}
static AsfPayload *
asf_payload_find_previous_fragment (AsfPayload * payload, AsfStream * stream)
{
AsfPayload *ret;
if (stream->payloads->len == 0) {
GST_DEBUG ("No previous fragments to merge with for stream %u", stream->id);
return NULL;
}
ret =
&g_array_index (stream->payloads, AsfPayload, stream->payloads->len - 1);
if (ret->mo_size != payload->mo_size ||
ret->mo_number != payload->mo_number || ret->mo_offset != 0) {
GST_WARNING ("Previous fragment does not match continued fragment");
return NULL;
}
#if 0
if (this_fragment->mo_offset + this_payload_len > first_fragment->mo_size) {
GST_WARNING ("Merged fragments would be bigger than the media object");
return FALSE;
}
#endif
return ret;
}
/* TODO: if we have another payload already queued for this stream and that
* payload doesn't have a duration, maybe we can calculate a duration for it
* (if the previous timestamp is smaller etc. etc.) */
static void
gst_asf_payload_queue_for_stream (GstASFDemux * demux, AsfPayload * payload,
AsfStream * stream)
{
/* remember the first timestamp in the stream */
if (!GST_CLOCK_TIME_IS_VALID (demux->first_ts) &&
GST_CLOCK_TIME_IS_VALID (payload->ts)) {
GST_DEBUG_OBJECT (demux, "first ts: %" GST_TIME_FORMAT,
GST_TIME_ARGS (payload->ts));
demux->first_ts = payload->ts;
if (demux->streaming) {
gst_segment_set_seek (&demux->segment, demux->segment.rate,
GST_FORMAT_TIME, demux->segment.flags, GST_SEEK_TYPE_SET,
demux->first_ts, GST_SEEK_TYPE_NONE, 0, NULL);
}
}
/* better drop a few frames at the beginning than send bogus timestamps */
if (G_UNLIKELY (payload->ts < demux->first_ts)) {
GST_LOG_OBJECT (stream->pad, "Dropping payload with timestamp %"
GST_TIME_FORMAT " which is before the first timestamp %"
GST_TIME_FORMAT, GST_TIME_ARGS (payload->ts),
GST_TIME_ARGS (demux->first_ts));
gst_buffer_replace (&payload->buf, NULL);
return;
}
/* make timestamps start from 0 */
if (!demux->streaming)
payload->ts -= demux->first_ts;
/* remove any incomplete payloads that will never be completed */
while (stream->payloads->len > 0) {
AsfPayload *prev;
guint idx_last;
idx_last = stream->payloads->len - 1;
prev = &g_array_index (stream->payloads, AsfPayload, idx_last);
if (gst_asf_payload_is_complete (prev))
break;
GST_DEBUG_OBJECT (demux, "Dropping incomplete fragmented media object "
"queued for stream %u", stream->id);
gst_buffer_replace (&prev->buf, NULL);
g_array_remove_index (stream->payloads, idx_last);
/* there's data missing, so there's a discontinuity now */
GST_BUFFER_FLAG_SET (payload->buf, GST_BUFFER_FLAG_DISCONT);
}
/* If we're about to queue a key frame that is before the segment start, we
* can ditch any previously queued payloads (which would also be before the
* segment start). This makes sure the decoder doesn't decode more than
* absolutely necessary after a seek (we don't push out payloads that are
* before the segment start until we have at least one that falls within the
* segment) */
if (GST_CLOCK_TIME_IS_VALID (payload->ts) &&
payload->ts < demux->segment.start && payload->keyframe) {
GST_DEBUG_OBJECT (demux, "Queueing keyframe before segment start, removing"
" %u previously-queued payloads, which would be out of segment too and"
" hence don't have to be decoded", stream->payloads->len);
while (stream->payloads->len > 0) {
AsfPayload *last;
guint idx_last;
idx_last = stream->payloads->len - 1;
last = &g_array_index (stream->payloads, AsfPayload, idx_last);
gst_buffer_replace (&last->buf, NULL);
g_array_remove_index (stream->payloads, idx_last);
}
/* Mark discontinuity (should be done via stream->discont anyway though) */
GST_BUFFER_FLAG_SET (payload->buf, GST_BUFFER_FLAG_DISCONT);
}
g_array_append_vals (stream->payloads, payload, 1);
}
static void
asf_payload_parse_replicated_data_extensions (AsfStream * stream,
AsfPayload * payload)
{
AsfPayloadExtension *ext;
guint off;
if (!stream->ext_props.valid || stream->ext_props.payload_extensions == NULL)
return;
off = 8;
for (ext = stream->ext_props.payload_extensions; ext->len > 0; ++ext) {
if (off + ext->len > payload->rep_data_len) {
GST_WARNING ("not enough replicated data for defined extensions");
return;
}
switch (ext->id) {
case ASF_PAYLOAD_EXTENSION_DURATION:
if (ext->len == 2) {
payload->duration =
GST_READ_UINT16_LE (payload->rep_data + off) * GST_MSECOND;
} else {
GST_WARNING ("unexpected DURATION extensions len %u", ext->len);
}
break;
default:
break;
}
off += ext->len;
}
}
static gboolean
gst_asf_demux_parse_payload (GstASFDemux * demux, AsfPacket * packet,
gint lentype, const guint8 ** p_data, guint * p_size)
{
AsfPayload payload = { 0, };
AsfStream *stream;
gboolean is_compressed;
guint payload_len;
guint stream_num;
if (*p_size < 1) {
GST_WARNING_OBJECT (demux, "Short packet!");
return FALSE;
}
stream_num = GST_READ_UINT8 (*p_data) & 0x7f;
payload.keyframe = ((GST_READ_UINT8 (*p_data) & 0x80) != 0);
*p_data += 1;
*p_size -= 1;
payload.ts = GST_CLOCK_TIME_NONE;
payload.duration = GST_CLOCK_TIME_NONE;
payload.mo_number =
asf_packet_read_varlen_int (packet->prop_flags, 4, p_data, p_size);
payload.mo_offset =
asf_packet_read_varlen_int (packet->prop_flags, 2, p_data, p_size);
payload.rep_data_len =
asf_packet_read_varlen_int (packet->prop_flags, 0, p_data, p_size);
is_compressed = (payload.rep_data_len == 1);
GST_LOG_OBJECT (demux, "payload for stream %u", stream_num);
GST_LOG_OBJECT (demux, "keyframe : %s", (payload.keyframe) ? "yes" : "no");
GST_LOG_OBJECT (demux, "compressed : %s", (is_compressed) ? "yes" : "no");
if (*p_size < payload.rep_data_len) {
GST_WARNING_OBJECT (demux, "Short packet! rep_data_len=%u, size=%u",
payload.rep_data_len, *p_size);
return FALSE;
}
memcpy (payload.rep_data, *p_data,
MIN (sizeof (payload.rep_data), payload.rep_data_len));
*p_data += payload.rep_data_len;
*p_size -= payload.rep_data_len;
if (*p_size == 0) {
GST_WARNING_OBJECT (demux, "payload without data!?");
return FALSE;
}
/* we use -1 as lentype for a single payload that's the size of the packet */
if (lentype >= 0 && lentype <= 3) {
payload_len = asf_packet_read_varlen_int (lentype, 0, p_data, p_size);
if (*p_size < payload_len) {
GST_WARNING_OBJECT (demux, "Short packet! payload_len=%u, size=%u",
payload_len, *p_size);
return FALSE;
}
} else {
payload_len = *p_size;
}
GST_LOG_OBJECT (demux, "payload length: %u", payload_len);
stream = gst_asf_demux_get_stream (demux, stream_num);
if (stream == NULL) {
GST_WARNING_OBJECT (demux, "Payload for unknown stream %u, skipping",
stream_num);
*p_data += payload_len;
*p_size -= payload_len;
return TRUE;
}
if (!is_compressed) {
GST_LOG_OBJECT (demux, "replicated data length: %u", payload.rep_data_len);
if (payload.rep_data_len >= 8) {
payload.mo_size = GST_READ_UINT32_LE (payload.rep_data);
payload.ts = GST_READ_UINT32_LE (payload.rep_data + 4) * GST_MSECOND;
payload.ts -= demux->preroll * GST_MSECOND;
asf_payload_parse_replicated_data_extensions (stream, &payload);
GST_LOG_OBJECT (demux, "media object size : %u", payload.mo_size);
GST_LOG_OBJECT (demux, "media object ts : %" GST_TIME_FORMAT,
GST_TIME_ARGS (payload.ts));
GST_LOG_OBJECT (demux, "media object dur : %" GST_TIME_FORMAT,
GST_TIME_ARGS (payload.duration));
} else if (payload.rep_data_len != 0) {
GST_WARNING_OBJECT (demux, "invalid replicated data length, very bad");
*p_data += payload_len;
*p_size -= payload_len;
return FALSE;
}
GST_LOG_OBJECT (demux, "media object offset : %u", payload.mo_offset);
GST_LOG_OBJECT (demux, "payload length: %u", payload_len);
if ((stream = gst_asf_demux_get_stream (demux, stream_num))) {
payload.buf = asf_packet_create_payload_buffer (packet, p_data, p_size,
payload_len);
/* n-th fragment of a fragmented media object? */
if (payload.mo_offset != 0) {
AsfPayload *prev;
if ((prev = asf_payload_find_previous_fragment (&payload, stream))) {
if (payload.mo_offset != GST_BUFFER_SIZE (prev->buf)) {
GST_WARNING_OBJECT (demux, "Offset doesn't match previous data?!");
}
/* note: buffer join/merge might not preserve buffer flags */
prev->buf = gst_buffer_join (prev->buf, payload.buf);
GST_LOG_OBJECT (demux, "Merged fragments, merged size: %u",
GST_BUFFER_SIZE (prev->buf));
} else {
gst_buffer_unref (payload.buf);
}
payload.buf = NULL;
} else {
gst_asf_payload_queue_for_stream (demux, &payload, stream);
}
}
} else {
const guint8 *payload_data;
GstClockTime ts, ts_delta;
guint num;
GST_LOG_OBJECT (demux, "Compressed payload, length=%u", payload_len);
payload_data = *p_data;
*p_data += payload_len;
*p_size -= payload_len;
ts = (payload.mo_offset - demux->preroll) * GST_MSECOND;
ts_delta = payload.rep_data[0] * GST_MSECOND;
for (num = 0; payload_len > 0; ++num) {
guint sub_payload_len;
sub_payload_len = GST_READ_UINT8 (payload_data);
GST_LOG_OBJECT (demux, "subpayload #%u: len=%u, ts=%" GST_TIME_FORMAT,
num, sub_payload_len, GST_TIME_ARGS (ts));
++payload_data;
--payload_len;
if (payload_len < sub_payload_len) {
GST_WARNING_OBJECT (demux, "Short payload! %u bytes left", payload_len);
return FALSE;
}
if (sub_payload_len > 0) {
payload.buf = asf_packet_create_payload_buffer (packet,
&payload_data, &payload_len, sub_payload_len);
payload.ts = ts;
payload.duration = ts_delta;
gst_asf_payload_queue_for_stream (demux, &payload, stream);
}
ts += ts_delta;
}
}
return TRUE;
}
gboolean
gst_asf_demux_parse_packet (GstASFDemux * demux, GstBuffer * buf)
{
AsfPacket packet = { 0, };
const guint8 *data;
gboolean has_multiple_payloads;
gboolean ret = TRUE;
guint8 ec_flags, flags1;
guint size;
data = GST_BUFFER_DATA (buf);
size = GST_BUFFER_SIZE (buf);
/* need at least two payload flag bytes, send time, and duration */
if (size < 2 + 4 + 2)
goto short_packet;
packet.buf = buf;
ec_flags = GST_READ_UINT8 (data);
/* skip optional error correction stuff */
if ((ec_flags & 0x80) != 0) {
guint ec_len_type, ec_len;
ec_len_type = (ec_flags & 0x60) >> 5;
if (ec_len_type == 0) {
ec_len = ec_flags & 0x0f;
} else {
GST_WARNING_OBJECT (demux, "unexpected error correction length type %u",
ec_len_type);
ec_len = 2;
}
GST_LOG ("packet has error correction (%u bytes)", ec_len);
/* still need at least two payload flag bytes, send time, and duration */
if (size <= (1 + ec_len) + 2 + 4 + 2)
goto short_packet;
data += 1 + ec_len;
size -= 1 + ec_len;
}
/* parse payload info */
flags1 = GST_READ_UINT8 (data);
packet.prop_flags = GST_READ_UINT8 (data + 1);
data += 2;
size -= 2;
has_multiple_payloads = (flags1 & 0x01) != 0;
packet.length = asf_packet_read_varlen_int (flags1, 5, &data, &size);
packet.sequence = asf_packet_read_varlen_int (flags1, 1, &data, &size);
packet.padding = asf_packet_read_varlen_int (flags1, 3, &data, &size);
if (size < 6)
goto short_packet;
packet.send_time = GST_READ_UINT32_LE (data) * GST_MSECOND;
packet.duration = GST_READ_UINT16_LE (data + 4) * GST_MSECOND;
data += 4 + 2;
size -= 4 + 2;
GST_LOG_OBJECT (demux, "multiple payloads: %u", has_multiple_payloads);
GST_LOG_OBJECT (demux, "packet length : %u", packet.length);
GST_LOG_OBJECT (demux, "sequence : %u", packet.sequence);
GST_LOG_OBJECT (demux, "padding : %u", packet.padding);
GST_LOG_OBJECT (demux, "send time : %" GST_TIME_FORMAT,
GST_TIME_ARGS (packet.send_time));
GST_LOG_OBJECT (demux, "duration : %" GST_TIME_FORMAT,
GST_TIME_ARGS (packet.duration));
if (packet.padding == (guint) - 1 || size < packet.padding)
goto short_packet;
size -= packet.padding;
/* adjust available size for parsing if there's less actual packet data for
* parsing than there is data in bytes (for sample see bug 431318) */
if (packet.length != 0 && packet.length < demux->packet_size) {
GST_LOG_OBJECT (demux, "shortened packet, adjusting available data size");
size -= (demux->packet_size - packet.length);
}
if (has_multiple_payloads) {
guint i, num, lentype;
if (size < 1)
goto short_packet;
num = (GST_READ_UINT8 (data) & 0x3F) >> 0;
lentype = (GST_READ_UINT8 (data) & 0xC0) >> 6;
++data;
--size;
GST_LOG_OBJECT (demux, "num payloads : %u", num);
for (i = 0; i < num; ++i) {
GST_LOG_OBJECT (demux, "Parsing payload %u/%u", i + 1, num);
ret = gst_asf_demux_parse_payload (demux, &packet, lentype, &data, &size);
if (!ret) {
GST_WARNING_OBJECT (demux, "Failed to parse payload %u/%u", i + 1, num);
break;
}
}
} else {
GST_LOG_OBJECT (demux, "Parsing single payload");
ret = gst_asf_demux_parse_payload (demux, &packet, -1, &data, &size);
}
return ret;
/* ERRORS */
short_packet:
{
GST_WARNING_OBJECT (demux, "Short packet!");
return FALSE;
}
}