gstreamer/gst/rtp/gstrtpdvdepay.c
2011-11-11 12:25:01 +01:00

418 lines
12 KiB
C

/* Farsight
* Copyright (C) 2006 Marcel Moreaux <marcelm@spacelabs.nl>
* (C) 2008 Wim Taymans <wim.taymans@gmail.com>
*
* 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.
*/
/*
* RTP DV depayloader.
*
* Important note for NTSC-users:
*
* Because the author uses PAL video, and he does not have proper DV
* documentation (the DV format specification is not freely available),
* this code may very well contain PAL-specific assumptions.
*/
#include <stdlib.h>
#include <string.h>
#include <gst/gst.h>
#include "gstrtpdvdepay.h"
GST_DEBUG_CATEGORY (rtpdvdepay_debug);
#define GST_CAT_DEFAULT (rtpdvdepay_debug)
/* Filter signals and args */
enum
{
/* FILL ME */
LAST_SIGNAL
};
enum
{
ARG_0,
};
static GstStaticPadTemplate src_factory = GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("video/x-dv")
);
static GstStaticPadTemplate sink_factory = GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("application/x-rtp, "
"media = (string) { \"video\", \"audio\" },"
"payload = (int) " GST_RTP_PAYLOAD_DYNAMIC_STRING ", "
"encoding-name = (string) \"DV\", "
"clock-rate = (int) 90000,"
"encode = (string) { \"SD-VCR/525-60\", \"SD-VCR/625-50\", \"HD-VCR/1125-60\","
"\"HD-VCR/1250-50\", \"SDL-VCR/525-60\", \"SDL-VCR/625-50\","
"\"306M/525-60\", \"306M/625-50\", \"314M-25/525-60\","
"\"314M-25/625-50\", \"314M-50/525-60\", \"314M-50/625-50\" }"
/* optional parameters can't go in the template
* "audio = (string) { \"bundled\", \"none\" }"
*/
)
);
static GstStateChangeReturn
gst_rtp_dv_depay_change_state (GstElement * element, GstStateChange transition);
static GstBuffer *gst_rtp_dv_depay_process (GstRTPBaseDepayload * base,
GstBuffer * in);
static gboolean gst_rtp_dv_depay_setcaps (GstRTPBaseDepayload * depayload,
GstCaps * caps);
#define gst_rtp_dv_depay_parent_class parent_class
G_DEFINE_TYPE (GstRTPDVDepay, gst_rtp_dv_depay, GST_TYPE_RTP_BASE_DEPAYLOAD);
static void
gst_rtp_dv_depay_class_init (GstRTPDVDepayClass * klass)
{
GstElementClass *gstelement_class = (GstElementClass *) klass;
GstRTPBaseDepayloadClass *gstrtpbasedepayload_class =
(GstRTPBaseDepayloadClass *) klass;
GST_DEBUG_CATEGORY_INIT (rtpdvdepay_debug, "rtpdvdepay", 0,
"DV RTP Depayloader");
gstelement_class->change_state =
GST_DEBUG_FUNCPTR (gst_rtp_dv_depay_change_state);
gst_element_class_add_pad_template (gstelement_class,
gst_static_pad_template_get (&src_factory));
gst_element_class_add_pad_template (gstelement_class,
gst_static_pad_template_get (&sink_factory));
gst_element_class_set_details_simple (gstelement_class, "RTP DV Depayloader",
"Codec/Depayloader/Network/RTP",
"Depayloads DV from RTP packets (RFC 3189)",
"Marcel Moreaux <marcelm@spacelabs.nl>, Wim Taymans <wim.taymans@gmail.com>");
gstrtpbasedepayload_class->process =
GST_DEBUG_FUNCPTR (gst_rtp_dv_depay_process);
gstrtpbasedepayload_class->set_caps =
GST_DEBUG_FUNCPTR (gst_rtp_dv_depay_setcaps);
}
/* initialize the new element
* instantiate pads and add them to element
* set functions
* initialize structure
*/
static void
gst_rtp_dv_depay_init (GstRTPDVDepay * filter)
{
}
static gboolean
parse_encode (GstRTPDVDepay * rtpdvdepay, const gchar * encode)
{
rtpdvdepay->width = 720;
if (!strcmp (encode, "314M-25/525-60")) {
rtpdvdepay->frame_size = 240000;
rtpdvdepay->height = 480;
rtpdvdepay->rate_num = 30000;
rtpdvdepay->rate_denom = 1001;
} else if (!strcmp (encode, "SD-VCR/525-60")) {
rtpdvdepay->frame_size = 120000;
rtpdvdepay->height = 480;
rtpdvdepay->rate_num = 30000;
rtpdvdepay->rate_denom = 1001;
} else if (!strcmp (encode, "314M-50/625-50")) {
rtpdvdepay->frame_size = 288000;
rtpdvdepay->height = 576;
rtpdvdepay->rate_num = 25;
rtpdvdepay->rate_denom = 1;
} else if (!strcmp (encode, "SD-VCR/625-50")) {
rtpdvdepay->frame_size = 144000;
rtpdvdepay->height = 576;
rtpdvdepay->rate_num = 25;
rtpdvdepay->rate_denom = 1;
} else if (!strcmp (encode, "314M-25/625-50")) {
rtpdvdepay->frame_size = 144000;
rtpdvdepay->height = 576;
rtpdvdepay->rate_num = 25;
rtpdvdepay->rate_denom = 1;
} else
rtpdvdepay->frame_size = -1;
return rtpdvdepay->frame_size != -1;
}
static gboolean
gst_rtp_dv_depay_setcaps (GstRTPBaseDepayload * depayload, GstCaps * caps)
{
GstStructure *structure;
GstRTPDVDepay *rtpdvdepay;
GstCaps *srccaps;
gint clock_rate;
gboolean systemstream, ret;
const gchar *encode, *media;
guint8 *data;
gsize size;
rtpdvdepay = GST_RTP_DV_DEPAY (depayload);
structure = gst_caps_get_structure (caps, 0);
if (!gst_structure_get_int (structure, "clock-rate", &clock_rate))
clock_rate = 90000; /* default */
depayload->clock_rate = clock_rate;
/* we really need the encode property to figure out the frame size, it's also
* required by the spec */
if (!(encode = gst_structure_get_string (structure, "encode")))
goto no_encode;
/* figure out the size of one frame */
if (!parse_encode (rtpdvdepay, encode))
goto unknown_encode;
/* check the media, this tells us that the stream has video or not */
if (!(media = gst_structure_get_string (structure, "media")))
goto no_media;
systemstream = FALSE;
if (!strcmp (media, "audio")) {
/* we need a demuxer for audio only */
systemstream = TRUE;
} else if (!strcmp (media, "video")) {
const gchar *audio;
/* check the optional audio field, if it's present and set to bundled, we
* are dealing with a system stream. */
if ((audio = gst_structure_get_string (structure, "audio"))) {
if (!strcmp (audio, "bundled"))
systemstream = TRUE;
}
}
/* allocate accumulator */
rtpdvdepay->acc = gst_buffer_new_and_alloc (rtpdvdepay->frame_size);
/* Initialize the new accumulator frame.
* If the previous frame exists, copy that into the accumulator frame.
* This way, missing packets in the stream won't show up badly. */
data = gst_buffer_map (rtpdvdepay->acc, &size, NULL, GST_MAP_WRITE);
memset (data, 0, rtpdvdepay->frame_size);
gst_buffer_unmap (rtpdvdepay->acc, data, size);
srccaps = gst_caps_new_simple ("video/x-dv",
"systemstream", G_TYPE_BOOLEAN, systemstream,
"width", G_TYPE_INT, rtpdvdepay->width,
"height", G_TYPE_INT, rtpdvdepay->height,
"framerate", GST_TYPE_FRACTION, rtpdvdepay->rate_num,
rtpdvdepay->rate_denom, NULL);
ret = gst_pad_set_caps (depayload->srcpad, srccaps);
gst_caps_unref (srccaps);
return ret;
/* ERRORS */
no_encode:
{
GST_ERROR_OBJECT (rtpdvdepay, "required encode property not found in caps");
return FALSE;
}
unknown_encode:
{
GST_ERROR_OBJECT (rtpdvdepay, "unknown encode property %s found", encode);
return FALSE;
}
no_media:
{
GST_ERROR_OBJECT (rtpdvdepay, "required media property not found in caps");
return FALSE;
}
}
/* A DV frame consists of a bunch of 80-byte DIF blocks.
* Each DIF block contains a 3-byte header telling where in the DV frame the
* DIF block should go. We use this information to calculate its position.
*/
static guint
calculate_difblock_location (guint8 * block)
{
gint block_type, dif_sequence, dif_block;
guint location;
block_type = block[0] >> 5;
dif_sequence = block[1] >> 4;
dif_block = block[2];
location = dif_sequence * 150;
switch (block_type) {
case 0: /* Header block, no offset */
break;
case 1: /* Subcode block */
location += (1 + dif_block);
break;
case 2: /* VAUX block */
location += (3 + dif_block);
break;
case 3: /* Audio block */
location += (6 + dif_block * 16);
break;
case 4: /* Video block */
location += (7 + (dif_block / 15) + dif_block);
break;
default: /* Something bogus */
GST_DEBUG ("UNKNOWN BLOCK");
location = -1;
break;
}
return location;
}
/* Process one RTP packet. Accumulate RTP payload in the proper place in a DV
* frame, and return that frame if we detect a new frame, or NULL otherwise.
* We assume a DV frame is 144000 bytes. That should accomodate PAL as well as
* NTSC.
*/
static GstBuffer *
gst_rtp_dv_depay_process (GstRTPBaseDepayload * base, GstBuffer * in)
{
GstBuffer *out = NULL;
guint8 *payload;
guint32 rtp_ts;
guint payload_len, location;
GstRTPDVDepay *dvdepay = GST_RTP_DV_DEPAY (base);
gboolean marker;
GstRTPBuffer rtp = { NULL, };
gst_rtp_buffer_map (in, GST_MAP_READ, &rtp);
marker = gst_rtp_buffer_get_marker (&rtp);
/* Check if the received packet contains (the start of) a new frame, we do
* this by checking the RTP timestamp. */
rtp_ts = gst_rtp_buffer_get_timestamp (&rtp);
/* we cannot copy the packet yet if the marker is set, we will do that below
* after taking out the data */
if (dvdepay->prev_ts != -1 && rtp_ts != dvdepay->prev_ts && !marker) {
/* the timestamp changed */
GST_DEBUG_OBJECT (dvdepay, "new frame with ts %u, old ts %u", rtp_ts,
dvdepay->prev_ts);
/* return copy of accumulator. */
out = gst_buffer_copy (dvdepay->acc);
}
/* Extract the payload */
payload_len = gst_rtp_buffer_get_payload_len (&rtp);
payload = gst_rtp_buffer_get_payload (&rtp);
/* copy all DIF chunks in their place. */
while (payload_len >= 80) {
guint offset;
/* Calculate where in the frame the payload should go */
location = calculate_difblock_location (payload);
if (location < 6) {
/* part of a header, set the flag to mark that we have the header. */
dvdepay->header_mask |= (1 << location);
GST_LOG_OBJECT (dvdepay, "got header at location %d, now %02x", location,
dvdepay->header_mask);
} else {
GST_LOG_OBJECT (dvdepay, "got block at location %d", location);
}
/* get the byte offset of the dif block */
offset = location * 80;
/* And copy it in, provided the location is sane. */
if (offset >= 0 && offset <= dvdepay->frame_size - 80)
gst_buffer_fill (dvdepay->acc, offset, payload, 80);
payload += 80;
payload_len -= 80;
}
gst_rtp_buffer_unmap (&rtp);
if (marker) {
GST_DEBUG_OBJECT (dvdepay, "marker bit complete frame %u", rtp_ts);
/* only copy the frame when we have a complete header */
if (dvdepay->header_mask == 0x3f) {
/* The marker marks the end of a frame that we need to push. The next frame
* will change the timestamp but we won't copy the accumulator again because
* we set the prev_ts to -1. */
out = gst_buffer_copy (dvdepay->acc);
} else {
GST_WARNING_OBJECT (dvdepay, "waiting for frame headers %02x",
dvdepay->header_mask);
}
dvdepay->prev_ts = -1;
} else {
/* save last timestamp */
dvdepay->prev_ts = rtp_ts;
}
return out;
}
static void
gst_rtp_dv_depay_reset (GstRTPDVDepay * depay)
{
if (depay->acc)
gst_buffer_unref (depay->acc);
depay->acc = NULL;
depay->prev_ts = -1;
depay->header_mask = 0;
}
static GstStateChangeReturn
gst_rtp_dv_depay_change_state (GstElement * element, GstStateChange transition)
{
GstStateChangeReturn ret;
GstRTPDVDepay *depay = GST_RTP_DV_DEPAY (element);
switch (transition) {
case GST_STATE_CHANGE_READY_TO_PAUSED:
gst_rtp_dv_depay_reset (depay);
break;
default:
break;
}
ret = GST_CALL_PARENT_WITH_DEFAULT (GST_ELEMENT_CLASS, change_state,
(element, transition), GST_STATE_CHANGE_FAILURE);
switch (transition) {
case GST_STATE_CHANGE_PAUSED_TO_READY:
gst_rtp_dv_depay_reset (depay);
break;
default:
break;
}
return ret;
}
gboolean
gst_rtp_dv_depay_plugin_init (GstPlugin * plugin)
{
return gst_element_register (plugin, "rtpdvdepay",
GST_RANK_SECONDARY, GST_TYPE_RTP_DV_DEPAY);
}