From 60d0dc07bfe9fa1735f31231ed43d81f64643a3a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= Date: Wed, 11 Mar 2009 19:33:38 +0100 Subject: mxfmux: Add support for muxing A-Law audio --- gst/mxf/mxfalaw.c | 174 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 174 insertions(+) diff --git a/gst/mxf/mxfalaw.c b/gst/mxf/mxfalaw.c index 074f1a48..db7456cb 100644 --- a/gst/mxf/mxfalaw.c +++ b/gst/mxf/mxfalaw.c @@ -29,6 +29,7 @@ #include #include "mxfalaw.h" +#include "mxfwrite.h" GST_DEBUG_CATEGORY_EXTERN (mxf_debug); #define GST_CAT_DEFAULT mxf_debug @@ -138,8 +139,181 @@ static const MXFEssenceElementHandler mxf_alaw_essence_element_handler = { mxf_alaw_create_caps }; +typedef struct +{ + guint64 error; + gint rate, channels; + MXFFraction edit_rate; +} ALawMappingData; + +static GstFlowReturn +mxf_alaw_write_func (GstBuffer * buffer, GstCaps * caps, gpointer mapping_data, + GstAdapter * adapter, GstBuffer ** outbuf, gboolean flush) +{ + ALawMappingData *md = mapping_data; + guint bytes; + + if (buffer) { + guint64 speu = + gst_util_uint64_scale (md->rate, md->edit_rate.d, md->edit_rate.n); + + md->error += (GST_SECOND * md->edit_rate.d * md->rate) % (md->edit_rate.n); + if (md->error >= md->edit_rate.n) { + md->error = 0; + speu += 1; + } + + bytes = speu * md->channels; + + gst_adapter_push (adapter, buffer); + if (gst_adapter_available (adapter) >= bytes) { + *outbuf = gst_adapter_take_buffer (adapter, bytes); + } + } else if (flush && (bytes = gst_adapter_available (adapter))) { + *outbuf = gst_adapter_take_buffer (adapter, bytes); + } + + return GST_FLOW_OK; +} + +static const guint8 alaw_essence_container_ul[] = { + 0x06, 0x0e, 0x2b, 0x34, 0x04, 0x01, 0x01, 0x03, + 0x0d, 0x01, 0x03, 0x01, 0x02, 0x0a, 0x01, 0x00 +}; + +static const MXFUL mxf_sound_essence_compression_alaw = + { {0x06, 0x0E, 0x2B, 0x34, 0x04, 0x01, 0x01, 0x03, 0x04, 0x02, 0x02, 0x02, + 0x03, 0x01, 0x01, 0x00} +}; + +static MXFMetadataFileDescriptor * +mxf_alaw_get_descriptor (GstPadTemplate * tmpl, GstCaps * caps, + MXFEssenceElementWriteFunc * handler, gpointer * mapping_data) +{ + MXFMetadataGenericSoundEssenceDescriptor *ret; + GstStructure *s; + ALawMappingData *md; + gint rate, channels; + + s = gst_caps_get_structure (caps, 0); + if (strcmp (gst_structure_get_name (s), "audio/x-alaw") != 0) + return NULL; + + if (!gst_structure_get_int (s, "rate", &rate) || + !gst_structure_get_int (s, "channels", &channels)) + return NULL; + + ret = (MXFMetadataGenericSoundEssenceDescriptor *) + gst_mini_object_new (MXF_TYPE_METADATA_GENERIC_SOUND_ESSENCE_DESCRIPTOR); + + memcpy (&ret->parent.essence_container, &alaw_essence_container_ul, 16); + memcpy (&ret->sound_essence_compression, &mxf_sound_essence_compression_alaw, + 16); + + mxf_metadata_generic_sound_essence_descriptor_from_caps (ret, caps); + *handler = mxf_alaw_write_func; + + md = g_new0 (ALawMappingData, 1); + md->rate = rate; + md->channels = channels; + *mapping_data = md; + + return (MXFMetadataFileDescriptor *) ret; +} + +static void +mxf_alaw_update_descriptor (MXFMetadataFileDescriptor * d, GstCaps * caps, + gpointer mapping_data, GstBuffer * buf) +{ + return; +} + +static guint +gst_greatest_common_divisor (guint a, guint b) +{ + while (b != 0) { + guint temp = a; + + a = b; + b = temp % b; + } + + return a; +} + +static void +mxf_alaw_get_edit_rate (MXFMetadataFileDescriptor * a, GstCaps * caps, + gpointer mapping_data, GstBuffer * buf, MXFMetadataSourcePackage * package, + MXFMetadataTimelineTrack * track, MXFFraction * edit_rate) +{ + guint i; + gdouble min = G_MAXDOUBLE; + MXFMetadataGenericSoundEssenceDescriptor *d = + MXF_METADATA_GENERIC_SOUND_ESSENCE_DESCRIPTOR (a); + ALawMappingData *md = mapping_data; + + for (i = 0; i < package->parent.n_tracks; i++) { + MXFMetadataTimelineTrack *tmp; + + if (!MXF_IS_METADATA_TIMELINE_TRACK (package->parent.tracks[i]) || + package->parent.tracks[i] == (MXFMetadataTrack *) track) + continue; + + tmp = MXF_METADATA_TIMELINE_TRACK (package->parent.tracks[i]); + if (((gdouble) tmp->edit_rate.n) / ((gdouble) tmp->edit_rate.d) < min) { + min = ((gdouble) tmp->edit_rate.n) / ((gdouble) tmp->edit_rate.d); + memcpy (edit_rate, &tmp->edit_rate, sizeof (MXFFraction)); + } + } + + if (min == G_MAXDOUBLE) { + guint32 nu, de; + guint gcd; + + /* 50ms edit units */ + nu = d->audio_sampling_rate.n; + de = d->audio_sampling_rate.d * 20; + gcd = gst_greatest_common_divisor (nu, de); + nu /= gcd; + de /= gcd; + + (*edit_rate).n = nu; + (*edit_rate).d = de; + } + + memcpy (&md->edit_rate, edit_rate, sizeof (MXFFraction)); +} + +static guint32 +mxf_alaw_get_track_number_template (MXFMetadataFileDescriptor * a, + GstCaps * caps, gpointer mapping_data) +{ + return (0x16 << 24) | (0x08 << 8); +} + +static MXFEssenceElementWriter mxf_alaw_essence_element_writer = { + mxf_alaw_get_descriptor, + mxf_alaw_update_descriptor, + mxf_alaw_get_edit_rate, + mxf_alaw_get_track_number_template, + NULL, + {{0,}} +}; + +#define ALAW_CAPS \ + "audio/x-alaw, " \ + "rate = (int) [ 8000, 192000 ], " \ + "channels = (int) [ 1, 2 ]" + void mxf_alaw_init (void) { mxf_essence_element_handler_register (&mxf_alaw_essence_element_handler); + + mxf_alaw_essence_element_writer.pad_template = + gst_pad_template_new ("alaw_audio_sink_%u", GST_PAD_SINK, GST_PAD_REQUEST, + gst_caps_from_string (ALAW_CAPS)); + memcpy (&mxf_alaw_essence_element_writer.data_definition, + mxf_metadata_track_identifier_get (MXF_METADATA_TRACK_SOUND_ESSENCE), 16); + mxf_essence_element_writer_register (&mxf_alaw_essence_element_writer); } -- cgit v1.2.1