gstreamer/gst/mxf/mxfd10.c
Sebastian Dröge 6208795598 mxfdemux: Add keyframe detection for MPEG2 video streams
This is useful for seeking as we usually want to seek to the previous
keyframe. The keyframe detection is done by parsing the MPEG2
elementary stream and if a GOP or I-frame packet is found we
assume a keyframe in this edit unit.
2009-02-06 09:53:13 +01:00

259 lines
7.3 KiB
C

/* GStreamer
* Copyright (C) 2008-2009 Sebastian Dröge <sebastian.droege@collabora.co.uk>
*
* 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.
*/
/* Implementation of SMPTE 386M - Mapping Type-D10 essence data into the MXF
* Generic Container
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gst/gst.h>
#include <string.h>
#include "mxfd10.h"
#include "mxfmpeg.h"
GST_DEBUG_CATEGORY_EXTERN (mxf_debug);
#define GST_CAT_DEFAULT mxf_debug
typedef struct
{
guint width, channels;
} MXFD10AudioMappingData;
static gboolean
mxf_is_d10_essence_track (const MXFMetadataTimelineTrack * track)
{
guint i;
g_return_val_if_fail (track != NULL, FALSE);
if (track->parent.descriptor == NULL)
return FALSE;
for (i = 0; i < track->parent.n_descriptor; i++) {
MXFMetadataFileDescriptor *d = track->parent.descriptor[i];
MXFUL *key;
if (!d)
continue;
key = &d->essence_container;
/* SMPTE 386M 5.1 */
if (mxf_is_generic_container_essence_container_label (key) &&
key->u[12] == 0x02 && key->u[13] == 0x01 &&
(key->u[14] >= 0x01 && key->u[14] <= 0x06) &&
(key->u[15] == 0x01 || key->u[15] == 0x02))
return TRUE;
}
return FALSE;
}
static GstFlowReturn
mxf_d10_picture_handle_essence_element (const MXFUL * key, GstBuffer * buffer,
GstCaps * caps,
MXFMetadataTimelineTrack * track,
gpointer mapping_data, GstBuffer ** outbuf)
{
*outbuf = buffer;
/* SMPTE 386M 5.2.1 */
if (key->u[12] != 0x05 || key->u[13] != 0x01 || key->u[14] != 0x01) {
GST_ERROR ("Invalid D10 picture essence element");
return GST_FLOW_ERROR;
}
if (mxf_mpeg_is_mpeg2_keyframe (buffer))
GST_BUFFER_FLAG_UNSET (buffer, GST_BUFFER_FLAG_DELTA_UNIT);
else
GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_DELTA_UNIT);
return GST_FLOW_OK;
}
static GstFlowReturn
mxf_d10_sound_handle_essence_element (const MXFUL * key, GstBuffer * buffer,
GstCaps * caps,
MXFMetadataTimelineTrack * track,
gpointer mapping_data, GstBuffer ** outbuf)
{
guint i, j, nsamples;
const guint8 *indata;
guint8 *outdata;
MXFD10AudioMappingData *data = mapping_data;
g_return_val_if_fail (data != NULL, GST_FLOW_ERROR);
g_return_val_if_fail (data->channels != 0
&& data->width != 0, GST_FLOW_ERROR);
/* SMPTE 386M 5.3.1 */
if (key->u[12] != 0x06 || key->u[13] != 0x01 || key->u[14] != 0x10) {
GST_ERROR ("Invalid D10 sound essence element");
return GST_FLOW_ERROR;
}
/* Now transform raw AES3 into raw audio, see SMPTE 331M */
if ((GST_BUFFER_SIZE (buffer) - 4) % 32 != 0) {
GST_ERROR ("Invalid D10 sound essence buffer size");
return GST_FLOW_ERROR;
}
nsamples = ((GST_BUFFER_SIZE (buffer) - 4) / 4) / 8;
*outbuf = gst_buffer_new_and_alloc (nsamples * data->width * data->channels);
gst_buffer_copy_metadata (*outbuf, buffer,
GST_BUFFER_COPY_FLAGS | GST_BUFFER_COPY_TIMESTAMPS |
GST_BUFFER_COPY_CAPS);
indata = GST_BUFFER_DATA (buffer);
outdata = GST_BUFFER_DATA (*outbuf);
/* Skip 32 bit header */
indata += 4;
for (i = 0; i < nsamples; i++) {
for (j = 0; j < data->channels; j++) {
guint32 in = GST_READ_UINT32_LE (indata);
/* Remove first 4 and last 4 bits as they only
* contain status data. Shift the 24 bit samples
* to the correct width afterwards. */
if (data->width == 2) {
in = (in >> 12) & 0xffff;
GST_WRITE_UINT16_LE (outdata, in);
} else if (data->width == 3) {
in = (in >> 4) & 0xffffff;
GST_WRITE_UINT24_LE (outdata, in);
}
indata += 4;
outdata += data->width;
}
/* There are always 8 channels but only the first
* ones contain valid data, skip the others */
indata += 4 * (8 - data->channels);
}
gst_buffer_unref (buffer);
return GST_FLOW_OK;
}
static GstCaps *
mxf_d10_create_caps (MXFMetadataTimelineTrack * track, GstTagList ** tags,
MXFEssenceElementHandleFunc * handler, gpointer * mapping_data)
{
MXFMetadataGenericPictureEssenceDescriptor *p = NULL;
MXFMetadataGenericSoundEssenceDescriptor *s = NULL;
guint i;
GstCaps *caps = NULL;
g_return_val_if_fail (track != NULL, NULL);
if (track->parent.descriptor == NULL) {
GST_ERROR ("No descriptor found for this track");
return NULL;
}
for (i = 0; i < track->parent.n_descriptor; i++) {
if (!track->parent.descriptor[i])
continue;
if (MXF_IS_METADATA_GENERIC_PICTURE_ESSENCE_DESCRIPTOR (track->parent.
descriptor[i])) {
p = (MXFMetadataGenericPictureEssenceDescriptor *) track->
parent.descriptor[i];
break;
} else if (MXF_IS_METADATA_GENERIC_SOUND_ESSENCE_DESCRIPTOR (track->parent.
descriptor[i])) {
s = (MXFMetadataGenericSoundEssenceDescriptor *) track->
parent.descriptor[i];
break;
}
}
if (!s && !p) {
GST_ERROR ("No descriptor found for this track");
return NULL;
}
if (!*tags)
*tags = gst_tag_list_new ();
if (s) {
MXFD10AudioMappingData *data;
if (s->channel_count == 0 ||
s->quantization_bits == 0 ||
s->audio_sampling_rate.n == 0 || s->audio_sampling_rate.d == 0) {
GST_ERROR ("Invalid descriptor");
return NULL;
}
if (s->quantization_bits != 16 && s->quantization_bits != 24) {
GST_ERROR ("Invalid width %u", s->quantization_bits);
return NULL;
}
/* FIXME: set channel layout */
caps = gst_caps_new_simple ("audio/x-raw-int",
"signed", G_TYPE_BOOLEAN,
(s->quantization_bits != 8), "endianness", G_TYPE_INT, G_LITTLE_ENDIAN,
"depth", G_TYPE_INT, s->quantization_bits, "width", G_TYPE_INT,
s->quantization_bits, NULL);
mxf_metadata_generic_sound_essence_descriptor_set_caps (s, caps);
*handler = mxf_d10_sound_handle_essence_element;
data = g_new0 (MXFD10AudioMappingData, 1);
data->width = s->quantization_bits / 8;
data->channels = s->channel_count;
*mapping_data = data;
gst_tag_list_add (*tags, GST_TAG_MERGE_APPEND, GST_TAG_VIDEO_CODEC,
"SMPTE D-10 Audio", NULL);
} else if (p) {
caps =
gst_caps_new_simple ("video/mpeg", "systemstream", G_TYPE_BOOLEAN,
FALSE, "mpegversion", G_TYPE_INT, 2, NULL);
mxf_metadata_generic_picture_essence_descriptor_set_caps (p, caps);
*handler = mxf_d10_picture_handle_essence_element;
gst_tag_list_add (*tags, GST_TAG_MERGE_APPEND, GST_TAG_VIDEO_CODEC,
"SMPTE D-10 Video", NULL);
}
return caps;
}
static const MXFEssenceElementHandler mxf_d10_essence_element_handler = {
mxf_is_d10_essence_track,
mxf_d10_create_caps
};
void
mxf_d10_init (void)
{
mxf_essence_element_handler_register (&mxf_d10_essence_element_handler);
}