diff options
Diffstat (limited to 'gst/audioparsers/gstac3parse.c')
| -rw-r--r-- | gst/audioparsers/gstac3parse.c | 958 |
1 files changed, 958 insertions, 0 deletions
diff --git a/gst/audioparsers/gstac3parse.c b/gst/audioparsers/gstac3parse.c new file mode 100644 index 0000000000..64b3ca3c1e --- /dev/null +++ b/gst/audioparsers/gstac3parse.c @@ -0,0 +1,958 @@ +/* GStreamer AC3 parser + * Copyright (C) 2009 Tim-Philipp Müller <tim centricular net> + * Copyright (C) 2009 Mark Nauwelaerts <mnauw users sf net> + * Copyright (C) 2009 Nokia Corporation. All rights reserved. + * Contact: Stefan Kost <stefan.kost@nokia.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., 51 Franklin St, Fifth Floor, + * Boston, MA 02110-1301, USA. + */ +/** + * SECTION:element-ac3parse + * @title: ac3parse + * @short_description: AC3 parser + * @see_also: #GstAmrParse, #GstAACParse + * + * This is an AC3 parser. + * + * ## Example launch line + * |[ + * gst-launch-1.0 filesrc location=abc.ac3 ! ac3parse ! a52dec ! audioresample ! audioconvert ! autoaudiosink + * ]| + * + */ + +/* TODO: + * - audio/ac3 to audio/x-private1-ac3 is not implemented (done in the muxer) + * - should accept framed and unframed input (needs decodebin fixes first) + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <string.h> + +#include "gstaudioparserselements.h" +#include "gstac3parse.h" +#include <gst/base/base.h> +#include <gst/pbutils/pbutils.h> + +GST_DEBUG_CATEGORY_STATIC (ac3_parse_debug); +#define GST_CAT_DEFAULT ac3_parse_debug + +static const struct +{ + const guint bit_rate; /* nominal bit rate */ + const guint frame_size[3]; /* frame size for 32kHz, 44kHz, and 48kHz */ +} frmsizcod_table[38] = { + { + 32, { + 64, 69, 96}}, { + 32, { + 64, 70, 96}}, { + 40, { + 80, 87, 120}}, { + 40, { + 80, 88, 120}}, { + 48, { + 96, 104, 144}}, { + 48, { + 96, 105, 144}}, { + 56, { + 112, 121, 168}}, { + 56, { + 112, 122, 168}}, { + 64, { + 128, 139, 192}}, { + 64, { + 128, 140, 192}}, { + 80, { + 160, 174, 240}}, { + 80, { + 160, 175, 240}}, { + 96, { + 192, 208, 288}}, { + 96, { + 192, 209, 288}}, { + 112, { + 224, 243, 336}}, { + 112, { + 224, 244, 336}}, { + 128, { + 256, 278, 384}}, { + 128, { + 256, 279, 384}}, { + 160, { + 320, 348, 480}}, { + 160, { + 320, 349, 480}}, { + 192, { + 384, 417, 576}}, { + 192, { + 384, 418, 576}}, { + 224, { + 448, 487, 672}}, { + 224, { + 448, 488, 672}}, { + 256, { + 512, 557, 768}}, { + 256, { + 512, 558, 768}}, { + 320, { + 640, 696, 960}}, { + 320, { + 640, 697, 960}}, { + 384, { + 768, 835, 1152}}, { + 384, { + 768, 836, 1152}}, { + 448, { + 896, 975, 1344}}, { + 448, { + 896, 976, 1344}}, { + 512, { + 1024, 1114, 1536}}, { + 512, { + 1024, 1115, 1536}}, { + 576, { + 1152, 1253, 1728}}, { + 576, { + 1152, 1254, 1728}}, { + 640, { + 1280, 1393, 1920}}, { + 640, { + 1280, 1394, 1920}} +}; + +static const guint fscod_rates[4] = { 48000, 44100, 32000, 0 }; +static const guint acmod_chans[8] = { 2, 1, 2, 3, 3, 4, 4, 5 }; +static const guint numblks[4] = { 1, 2, 3, 6 }; + +static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src", + GST_PAD_SRC, + GST_PAD_ALWAYS, + GST_STATIC_CAPS ("audio/x-ac3, framed = (boolean) true, " + " channels = (int) [ 1, 6 ], rate = (int) [ 8000, 48000 ], " + " alignment = (string) { iec61937, frame}; " + "audio/x-eac3, framed = (boolean) true, " + " channels = (int) [ 1, 6 ], rate = (int) [ 8000, 48000 ], " + " alignment = (string) { iec61937, frame}; ")); + +static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink", + GST_PAD_SINK, + GST_PAD_ALWAYS, + GST_STATIC_CAPS ("audio/x-ac3; " "audio/x-eac3; " "audio/ac3; " + "audio/x-private1-ac3")); + +static void gst_ac3_parse_finalize (GObject * object); + +static gboolean gst_ac3_parse_start (GstBaseParse * parse); +static gboolean gst_ac3_parse_stop (GstBaseParse * parse); +static GstFlowReturn gst_ac3_parse_handle_frame (GstBaseParse * parse, + GstBaseParseFrame * frame, gint * skipsize); +static GstFlowReturn gst_ac3_parse_pre_push_frame (GstBaseParse * parse, + GstBaseParseFrame * frame); +static gboolean gst_ac3_parse_src_event (GstBaseParse * parse, + GstEvent * event); +static GstCaps *gst_ac3_parse_get_sink_caps (GstBaseParse * parse, + GstCaps * filter); +static gboolean gst_ac3_parse_set_sink_caps (GstBaseParse * parse, + GstCaps * caps); + +#define gst_ac3_parse_parent_class parent_class +G_DEFINE_TYPE (GstAc3Parse, gst_ac3_parse, GST_TYPE_BASE_PARSE); +GST_ELEMENT_REGISTER_DEFINE (ac3parse, "ac3parse", + GST_RANK_PRIMARY + 1, GST_TYPE_AC3_PARSE); + +static void +gst_ac3_parse_class_init (GstAc3ParseClass * klass) +{ + GObjectClass *object_class = G_OBJECT_CLASS (klass); + GstElementClass *element_class = GST_ELEMENT_CLASS (klass); + GstBaseParseClass *parse_class = GST_BASE_PARSE_CLASS (klass); + + GST_DEBUG_CATEGORY_INIT (ac3_parse_debug, "ac3parse", 0, + "AC3 audio stream parser"); + + object_class->finalize = gst_ac3_parse_finalize; + + gst_element_class_add_static_pad_template (element_class, &sink_template); + gst_element_class_add_static_pad_template (element_class, &src_template); + + gst_element_class_set_static_metadata (element_class, + "AC3 audio stream parser", "Codec/Parser/Converter/Audio", + "AC3 parser", "Tim-Philipp Müller <tim centricular net>"); + + parse_class->start = GST_DEBUG_FUNCPTR (gst_ac3_parse_start); + parse_class->stop = GST_DEBUG_FUNCPTR (gst_ac3_parse_stop); + parse_class->handle_frame = GST_DEBUG_FUNCPTR (gst_ac3_parse_handle_frame); + parse_class->pre_push_frame = + GST_DEBUG_FUNCPTR (gst_ac3_parse_pre_push_frame); + parse_class->src_event = GST_DEBUG_FUNCPTR (gst_ac3_parse_src_event); + parse_class->get_sink_caps = GST_DEBUG_FUNCPTR (gst_ac3_parse_get_sink_caps); + parse_class->set_sink_caps = GST_DEBUG_FUNCPTR (gst_ac3_parse_set_sink_caps); +} + +static void +gst_ac3_parse_reset (GstAc3Parse * ac3parse) +{ + ac3parse->channels = -1; + ac3parse->sample_rate = -1; + ac3parse->blocks = -1; + ac3parse->eac = FALSE; + ac3parse->sent_codec_tag = FALSE; + g_atomic_int_set (&ac3parse->align, GST_AC3_PARSE_ALIGN_NONE); +} + +static void +gst_ac3_parse_init (GstAc3Parse * ac3parse) +{ + gst_base_parse_set_min_frame_size (GST_BASE_PARSE (ac3parse), 8); + gst_ac3_parse_reset (ac3parse); + ac3parse->baseparse_chainfunc = + GST_BASE_PARSE_SINK_PAD (GST_BASE_PARSE (ac3parse))->chainfunc; + GST_PAD_SET_ACCEPT_INTERSECT (GST_BASE_PARSE_SINK_PAD (ac3parse)); + GST_PAD_SET_ACCEPT_TEMPLATE (GST_BASE_PARSE_SINK_PAD (ac3parse)); +} + +static void +gst_ac3_parse_finalize (GObject * object) +{ + G_OBJECT_CLASS (parent_class)->finalize (object); +} + +static gboolean +gst_ac3_parse_start (GstBaseParse * parse) +{ + GstAc3Parse *ac3parse = GST_AC3_PARSE (parse); + + GST_DEBUG_OBJECT (parse, "starting"); + + gst_ac3_parse_reset (ac3parse); + + return TRUE; +} + +static gboolean +gst_ac3_parse_stop (GstBaseParse * parse) +{ + GST_DEBUG_OBJECT (parse, "stopping"); + + return TRUE; +} + +static void +gst_ac3_parse_set_alignment (GstAc3Parse * ac3parse, gboolean eac) +{ + GstCaps *caps; + GstStructure *st; + const gchar *str = NULL; + int i; + + if (G_LIKELY (!eac)) + goto done; + + caps = gst_pad_get_allowed_caps (GST_BASE_PARSE_SRC_PAD (ac3parse)); + + if (!caps) + goto done; + + for (i = 0; i < gst_caps_get_size (caps); i++) { + st = gst_caps_get_structure (caps, i); + + if (!g_str_equal (gst_structure_get_name (st), "audio/x-eac3")) + continue; + + if ((str = gst_structure_get_string (st, "alignment"))) { + if (g_str_equal (str, "iec61937")) { + g_atomic_int_set (&ac3parse->align, GST_AC3_PARSE_ALIGN_IEC61937); + GST_DEBUG_OBJECT (ac3parse, "picked iec61937 alignment"); + } else if (g_str_equal (str, "frame") == 0) { + g_atomic_int_set (&ac3parse->align, GST_AC3_PARSE_ALIGN_FRAME); + GST_DEBUG_OBJECT (ac3parse, "picked frame alignment"); + } else { + g_atomic_int_set (&ac3parse->align, GST_AC3_PARSE_ALIGN_FRAME); + GST_WARNING_OBJECT (ac3parse, "unknown alignment: %s", str); + } + break; + } + } + + if (caps) + gst_caps_unref (caps); + +done: + /* default */ + if (ac3parse->align == GST_AC3_PARSE_ALIGN_NONE) { + g_atomic_int_set (&ac3parse->align, GST_AC3_PARSE_ALIGN_FRAME); + GST_DEBUG_OBJECT (ac3parse, "picked syncframe alignment"); + } +} + +static gboolean +gst_ac3_parse_frame_header_ac3 (GstAc3Parse * ac3parse, GstBuffer * buf, + gint skip, guint * frame_size, guint * rate, guint * chans, guint * blks, + guint * sid) +{ + GstBitReader bits; + GstMapInfo map; + guint8 fscod, frmsizcod, bsid, acmod, lfe_on, rate_scale; + gboolean ret = FALSE; + + GST_LOG_OBJECT (ac3parse, "parsing ac3"); + + gst_buffer_map (buf, &map, GST_MAP_READ); + gst_bit_reader_init (&bits, map.data, map.size); + gst_bit_reader_skip_unchecked (&bits, skip * 8); + + gst_bit_reader_skip_unchecked (&bits, 16 + 16); + fscod = gst_bit_reader_get_bits_uint8_unchecked (&bits, 2); + frmsizcod = gst_bit_reader_get_bits_uint8_unchecked (&bits, 6); + + if (G_UNLIKELY (fscod == 3 || frmsizcod >= G_N_ELEMENTS (frmsizcod_table))) { + GST_DEBUG_OBJECT (ac3parse, "bad fscod=%d frmsizcod=%d", fscod, frmsizcod); + goto cleanup; + } + + bsid = gst_bit_reader_get_bits_uint8_unchecked (&bits, 5); + gst_bit_reader_skip_unchecked (&bits, 3); /* bsmod */ + acmod = gst_bit_reader_get_bits_uint8_unchecked (&bits, 3); + + /* spec not quite clear here: decoder should decode if less than 8, + * but seemingly only defines 6 and 8 cases */ + /* Files with 9 and 10 happen, and seem to comply with the <= 8 + format, so let them through. The spec says nothing about 9 and 10 */ + if (bsid > 10) { + GST_DEBUG_OBJECT (ac3parse, "unexpected bsid=%d", bsid); + goto cleanup; + } else if (bsid != 8 && bsid != 6) { + GST_DEBUG_OBJECT (ac3parse, "undefined bsid=%d", bsid); + } + + if ((acmod & 0x1) && (acmod != 0x1)) /* 3 front channels */ + gst_bit_reader_skip_unchecked (&bits, 2); + if ((acmod & 0x4)) /* if a surround channel exists */ + gst_bit_reader_skip_unchecked (&bits, 2); + if (acmod == 0x2) /* if in 2/0 mode */ + gst_bit_reader_skip_unchecked (&bits, 2); + + lfe_on = gst_bit_reader_get_bits_uint8_unchecked (&bits, 1); + + /* 6/8->0, 9->1, 10->2, + see http://matroska.org/technical/specs/codecid/index.html */ + rate_scale = (CLAMP (bsid, 8, 10) - 8); + + if (frame_size) + *frame_size = frmsizcod_table[frmsizcod].frame_size[fscod] * 2; + if (rate) + *rate = fscod_rates[fscod] >> rate_scale; + if (chans) + *chans = acmod_chans[acmod] + lfe_on; + if (blks) + *blks = 6; + if (sid) + *sid = 0; + + ret = TRUE; + +cleanup: + gst_buffer_unmap (buf, &map); + + return ret; +} + +static gboolean +gst_ac3_parse_frame_header_eac3 (GstAc3Parse * ac3parse, GstBuffer * buf, + gint skip, guint * frame_size, guint * rate, guint * chans, guint * blks, + guint * sid) +{ + GstBitReader bits; + GstMapInfo map; + guint16 frmsiz, sample_rate, blocks; + guint8 strmtyp, fscod, fscod2, acmod, lfe_on, strmid, numblkscod; + gboolean ret = FALSE; + + GST_LOG_OBJECT (ac3parse, "parsing e-ac3"); + + gst_buffer_map (buf, &map, GST_MAP_READ); + gst_bit_reader_init (&bits, map.data, map.size); + gst_bit_reader_skip_unchecked (&bits, skip * 8); + + gst_bit_reader_skip_unchecked (&bits, 16); + strmtyp = gst_bit_reader_get_bits_uint8_unchecked (&bits, 2); /* strmtyp */ + if (G_UNLIKELY (strmtyp == 3)) { + GST_DEBUG_OBJECT (ac3parse, "bad strmtyp %d", strmtyp); + goto cleanup; + } + + strmid = gst_bit_reader_get_bits_uint8_unchecked (&bits, 3); /* substreamid */ + frmsiz = gst_bit_reader_get_bits_uint16_unchecked (&bits, 11); /* frmsiz */ + fscod = gst_bit_reader_get_bits_uint8_unchecked (&bits, 2); /* fscod */ + if (fscod == 3) { + fscod2 = gst_bit_reader_get_bits_uint8_unchecked (&bits, 2); /* fscod2 */ + if (G_UNLIKELY (fscod2 == 3)) { + GST_DEBUG_OBJECT (ac3parse, "invalid fscod2"); + goto cleanup; + } + sample_rate = fscod_rates[fscod2] / 2; + blocks = 6; + } else { + numblkscod = gst_bit_reader_get_bits_uint8_unchecked (&bits, 2); /* numblkscod */ + sample_rate = fscod_rates[fscod]; + blocks = numblks[numblkscod]; + } + + acmod = gst_bit_reader_get_bits_uint8_unchecked (&bits, 3); /* acmod */ + lfe_on = gst_bit_reader_get_bits_uint8_unchecked (&bits, 1); /* lfeon */ + + gst_bit_reader_skip_unchecked (&bits, 5); /* bsid */ + + if (frame_size) + *frame_size = (frmsiz + 1) * 2; + if (rate) + *rate = sample_rate; + if (chans) + *chans = acmod_chans[acmod] + lfe_on; + if (blks) + *blks = blocks; + if (sid) + *sid = (strmtyp & 0x1) << 3 | strmid; + + ret = TRUE; + +cleanup: + gst_buffer_unmap (buf, &map); + + return ret; +} + +static gboolean +gst_ac3_parse_frame_header (GstAc3Parse * parse, GstBuffer * buf, gint skip, + guint * framesize, guint * rate, guint * chans, guint * blocks, + guint * sid, gboolean * eac) +{ + GstBitReader bits; + guint16 sync; + guint8 bsid; + GstMapInfo map; + gboolean ret = FALSE; + + gst_buffer_map (buf, &map, GST_MAP_READ); + gst_bit_reader_init (&bits, map.data, map.size); + + GST_MEMDUMP_OBJECT (parse, "AC3 frame sync", map.data, MIN (map.size, 16)); + + gst_bit_reader_skip_unchecked (&bits, skip * 8); + + sync = gst_bit_reader_get_bits_uint16_unchecked (&bits, 16); + gst_bit_reader_skip_unchecked (&bits, 16 + 8); + bsid = gst_bit_reader_peek_bits_uint8_unchecked (&bits, 5); + + if (G_UNLIKELY (sync != 0x0b77)) + goto cleanup; + + GST_LOG_OBJECT (parse, "bsid = %d", bsid); + + if (bsid <= 10) { + if (eac) + *eac = FALSE; + ret = gst_ac3_parse_frame_header_ac3 (parse, buf, skip, framesize, rate, + chans, blocks, sid); + goto cleanup; + } else if (bsid <= 16) { + if (eac) + *eac = TRUE; + ret = gst_ac3_parse_frame_header_eac3 (parse, buf, skip, framesize, rate, + chans, blocks, sid); + goto cleanup; + } else { + GST_DEBUG_OBJECT (parse, "unexpected bsid %d", bsid); + ret = FALSE; + goto cleanup; + } + + GST_DEBUG_OBJECT (parse, "unexpected bsid %d", bsid); + +cleanup: + gst_buffer_unmap (buf, &map); + + return ret; +} + +static GstFlowReturn +gst_ac3_parse_handle_frame (GstBaseParse * parse, + GstBaseParseFrame * frame, gint * skipsize) +{ + GstAc3Parse *ac3parse = GST_AC3_PARSE (parse); + GstBuffer *buf = frame->buffer; + GstByteReader reader; + gint off; + gboolean lost_sync, draining, eac, more = FALSE; + guint frmsiz, blocks, sid; + guint rate, chans; + gboolean update_rate = FALSE; + gint framesize = 0; + gint have_blocks = 0; + GstMapInfo map; + gboolean ret = FALSE; + GstFlowReturn res = GST_FLOW_OK; + + gst_buffer_map (buf, &map, GST_MAP_READ); + + if (G_UNLIKELY (map.size < 8)) { + *skipsize = 1; + goto cleanup; + } + + gst_byte_reader_init (&reader, map.data, map.size); + off = gst_byte_reader_masked_scan_uint32 (&reader, 0xffff0000, 0x0b770000, + 0, map.size); + + GST_LOG_OBJECT (parse, "possible sync at buffer offset %d", off); + + /* didn't find anything that looks like a sync word, skip */ + if (off < 0) { + *skipsize = map.size - 3; + goto cleanup; + } + + /* possible frame header, but not at offset 0? skip bytes before sync */ + if (off > 0) { + *skipsize = off; + goto cleanup; + } + + /* make sure the values in the frame header look sane */ + if (!gst_ac3_parse_frame_header (ac3parse, buf, 0, &frmsiz, &rate, &chans, + &blocks, &sid, &eac)) { + *skipsize = off + 2; + goto cleanup; + } + + GST_LOG_OBJECT (parse, "size: %u, blocks: %u, rate: %u, chans: %u", frmsiz, + blocks, rate, chans); + + framesize = frmsiz; + + if (G_UNLIKELY (g_atomic_int_get (&ac3parse->align) == + GST_AC3_PARSE_ALIGN_NONE)) + gst_ac3_parse_set_alignment (ac3parse, eac); + + GST_LOG_OBJECT (parse, "got frame"); + + lost_sync = GST_BASE_PARSE_LOST_SYNC (parse); + draining = GST_BASE_PARSE_DRAINING (parse); + + if (g_atomic_int_get (&ac3parse->align) == GST_AC3_PARSE_ALIGN_IEC61937) { + /* We need 6 audio blocks from each substream, so we keep going forwards + * till we have it */ + + g_assert (blocks > 0); + GST_LOG_OBJECT (ac3parse, "Need %d frames before pushing", 6 / blocks); + + if (sid != 0) { + /* We need the first substream to be the one with id 0 */ + GST_LOG_OBJECT (ac3parse, "Skipping till we find sid 0"); + *skipsize = off + 2; + goto cleanup; + } + + framesize = 0; + + /* Loop till we have 6 blocks per substream */ + for (have_blocks = 0; !more && have_blocks < 6; have_blocks += blocks) { + /* Loop till we get one frame from each substream */ + do { + framesize += frmsiz; + + if (!gst_byte_reader_skip (&reader, frmsiz) + || map.size < (framesize + 6)) { + more = TRUE; + break; + } + + if (!gst_ac3_parse_frame_header (ac3parse, buf, framesize, &frmsiz, + NULL, NULL, NULL, &sid, &eac)) { + *skipsize = off + 2; + goto cleanup; + } + } while (sid); + } + + /* We're now at the next frame, so no need to skip if resyncing */ + frmsiz = 0; + } + + if (lost_sync && !draining) { + guint16 word = 0; + + GST_DEBUG_OBJECT (ac3parse, "resyncing; checking next frame syncword"); + + if (more || !gst_byte_reader_skip (&reader, frmsiz) || + !gst_byte_reader_get_uint16_be (&reader, &word)) { + GST_DEBUG_OBJECT (ac3parse, "... but not sufficient data"); + gst_base_parse_set_min_frame_size (parse, framesize + 8); + *skipsize = 0; + goto cleanup; + } else { + if (word != 0x0b77) { + GST_DEBUG_OBJECT (ac3parse, "0x%x not OK", word); + *skipsize = off + 2; + goto cleanup; + } else { + /* ok, got sync now, let's assume constant frame size */ + gst_base_parse_set_min_frame_size (parse, framesize); + } + } + } + + /* expect to have found a frame here */ + g_assert (framesize); + ret = TRUE; + + /* arrange for metadata setup */ + if (G_UNLIKELY (sid)) { + /* dependent frame, no need to (ac)count for or consider further */ + GST_LOG_OBJECT (parse, "sid: %d", sid); + frame->flags |= GST_BASE_PARSE_FRAME_FLAG_NO_FRAME; + /* TODO maybe also mark as DELTA_UNIT, + * if that does not surprise baseparse elsewhere */ + /* occupies same time space as previous base frame */ + if (G_LIKELY (GST_BUFFER_TIMESTAMP (buf) >= GST_BUFFER_DURATION (buf))) + GST_BUFFER_TIMESTAMP (buf) -= GST_BUFFER_DURATION (buf); + /* only shortcut if we already arranged for caps */ + if (G_LIKELY (ac3parse->sample_rate > 0)) + goto cleanup; + } + + if (G_UNLIKELY (ac3parse->sample_rate != rate || ac3parse->channels != chans + || ac3parse->eac != eac)) { + GstCaps *caps = gst_caps_new_simple (eac ? "audio/x-eac3" : "audio/x-ac3", + "framed", G_TYPE_BOOLEAN, TRUE, "rate", G_TYPE_INT, rate, + "channels", G_TYPE_INT, chans, NULL); + gst_caps_set_simple (caps, "alignment", G_TYPE_STRING, + g_atomic_int_get (&ac3parse->align) == GST_AC3_PARSE_ALIGN_IEC61937 ? + "iec61937" : "frame", NULL); + gst_pad_set_caps (GST_BASE_PARSE_SRC_PAD (parse), caps); + gst_caps_unref (caps); + + ac3parse->sample_rate = rate; + ac3parse->channels = chans; + ac3parse->eac = eac; + + update_rate = TRUE; + } + + if (G_UNLIKELY (ac3parse->blocks != blocks)) { + ac3parse->blocks = blocks; + + update_rate = TRUE; + } + + if (G_UNLIKELY (update_rate)) + gst_base_parse_set_frame_rate (parse, rate, 256 * blocks, 2, 2); + +cleanup: + gst_buffer_unmap (buf, &map); + + if (ret && framesize <= map.size) { + res = gst_base_parse_finish_frame (parse, frame, framesize); + } + + return res; +} + + +/* + * MPEG-PS private1 streams add a 2 bytes "Audio Substream Headers" for each + * buffer (not each frame) with the offset of the next frame's start. + * + * Buffer 1: + * ------------------------------------------- + * |firstAccUnit|AC3SyncWord|xxxxxxxxxxxxxxxxx + * ------------------------------------------- + * Buffer 2: + * ------------------------------------------- + * |firstAccUnit|xxxxxx|AC3SyncWord|xxxxxxxxxx + * ------------------------------------------- + * + * These 2 bytes can be dropped safely as they do not include any timing + * information, only the offset to the start of the next frame. + * + * From http://stnsoft.com/DVD/ass-hdr.html: + * "FirstAccUnit offset to frame which corresponds to PTS value offset 0 is the + * last byte of FirstAccUnit, ie add the offset of byte 2 to get the AU's offset + * The value 0000 indicates there is no first access unit" + * */ + +static GstFlowReturn +gst_ac3_parse_chain_priv (GstPad * pad, GstObject * parent, GstBuffer * buf) +{ + GstAc3Parse *ac3parse = GST_AC3_PARSE (parent); + GstFlowReturn ret; + gsize size; + guint8 data[2]; + gint offset; + gint len; + GstBuffer *subbuf; + gint first_access; + + size = gst_buffer_get_size (buf); + if (size < 2) + goto not_enough_data; + + gst_buffer_extract (buf, 0, data, 2); + first_access = (data[0] << 8) | data[1]; + + /* Skip the first_access header */ + offset = 2; + + if (first_access > 1) { + /* Length of data before first_access */ + len = first_access - 1; + + if (len <= 0 || offset + len > size) + goto bad_first_access_parameter; + + subbuf = gst_buffer_copy_region (buf, GST_BUFFER_COPY_ALL, offset, len); + GST_BUFFER_DTS (subbuf) = GST_CLOCK_TIME_NONE; + GST_BUFFER_PTS (subbuf) = GST_CLOCK_TIME_NONE; + ret = ac3parse->baseparse_chainfunc (pad, parent, subbuf); + if (ret != GST_FLOW_OK && ret != GST_FLOW_NOT_LINKED) { + gst_buffer_unref (buf); + goto done; + } + + offset += len; + len = size - offset; + + if (len > 0) { + subbuf = gst_buffer_copy_region (buf, GST_BUFFER_COPY_ALL, offset, len); + GST_BUFFER_PTS (subbuf) = GST_BUFFER_PTS (buf); + GST_BUFFER_DTS (subbuf) = GST_BUFFER_DTS (buf); + + ret = ac3parse->baseparse_chainfunc (pad, parent, subbuf); + } + gst_buffer_unref (buf); + } else { + /* first_access = 0 or 1, so if there's a timestamp it applies to the first byte */ + subbuf = + gst_buffer_copy_region (buf, GST_BUFFER_COPY_ALL, offset, + size - offset); + GST_BUFFER_PTS (subbuf) = GST_BUFFER_PTS (buf); + GST_BUFFER_DTS (subbuf) = GST_BUFFER_DTS (buf); + gst_buffer_unref (buf); + ret = ac3parse->baseparse_chainfunc (pad, parent, subbuf); + } + +done: + return ret; + +/* ERRORS */ +not_enough_data: + { + GST_ELEMENT_ERROR (GST_ELEMENT (ac3parse), STREAM, FORMAT, (NULL), + ("Insufficient data in buffer. Can't determine first_acess")); + gst_buffer_unref (buf); + return GST_FLOW_ERROR; + } +bad_first_access_parameter: + { + GST_ELEMENT_ERROR (GST_ELEMENT (ac3parse), STREAM, FORMAT, (NULL), + ("Bad first_access parameter (%d) in buffer", first_access)); + gst_buffer_unref (buf); + return GST_FLOW_ERROR; + } +} + +static GstFlowReturn +gst_ac3_parse_pre_push_frame (GstBaseParse * parse, GstBaseParseFrame * frame) +{ + GstAc3Parse *ac3parse = GST_AC3_PARSE (parse); + + if (!ac3parse->sent_codec_tag) { + GstTagList *taglist; + GstCaps *caps; + + /* codec tag */ + caps = gst_pad_get_current_caps (GST_BASE_PARSE_SRC_PAD (parse)); + if (G_UNLIKELY (caps == NULL)) { + if (GST_PAD_IS_FLUSHING (GST_BASE_PARSE_SRC_PAD (parse))) { + GST_INFO_OBJECT (parse, "Src pad is flushing"); + return GST_FLOW_FLUSHING; + } else { + GST_INFO_OBJECT (parse, "Src pad is not negotiated!"); + return GST_FLOW_NOT_NEGOTIATED; + } + } + + taglist = gst_tag_list_new_empty (); + gst_pb_utils_add_codec_description_to_tag_list (taglist, + GST_TAG_AUDIO_CODEC, caps); + gst_caps_unref (caps); + + gst_base_parse_merge_tags (parse, taglist, GST_TAG_MERGE_REPLACE); + gst_tag_list_unref (taglist); + + /* also signals the end of first-frame processing */ + ac3parse->sent_codec_tag = TRUE; + } + + frame->flags |= GST_BASE_PARSE_FRAME_FLAG_CLIP; + + return GST_FLOW_OK; +} + +static gboolean +gst_ac3_parse_src_event (GstBaseParse * parse, GstEvent * event) +{ + GstAc3Parse *ac3parse = GST_AC3_PARSE (parse); + + if (G_UNLIKELY (GST_EVENT_TYPE (event) == GST_EVENT_CUSTOM_UPSTREAM) && + gst_event_has_name (event, "ac3parse-set-alignment")) { + const GstStructure *st = gst_event_get_structure (event); + const gchar *align = gst_structure_get_string (st, "alignment"); + + if (g_str_equal (align, "iec61937")) { + GST_DEBUG_OBJECT (ac3parse, "Switching to iec61937 alignment"); + g_atomic_int_set (&ac3parse->align, GST_AC3_PARSE_ALIGN_IEC61937); + } else if (g_str_equal (align, "frame")) { + GST_DEBUG_OBJECT (ac3parse, "Switching to frame alignment"); + g_atomic_int_set (&ac3parse->align, GST_AC3_PARSE_ALIGN_FRAME); + } else { + g_atomic_int_set (&ac3parse->align, GST_AC3_PARSE_ALIGN_FRAME); + GST_WARNING_OBJECT (ac3parse, "Got unknown alignment request (%s) " + "reverting to frame alignment.", + gst_structure_get_string (st, "alignment")); + } + + gst_event_unref (event); + return TRUE; + } + + return GST_BASE_PARSE_CLASS (parent_class)->src_event (parse, event); +} + +static void +remove_fields (GstCaps * caps) +{ + guint i, n; + + n = gst_caps_get_size (caps); + for (i = 0; i < n; i++) { + GstStructure *s = gst_caps_get_structure (caps, i); + + gst_structure_remove_field (s, "framed"); + gst_structure_remove_field (s, "alignment"); + } +} + +static GstCaps * +extend_caps (GstCaps * caps, gboolean add_private) +{ + guint i, n; + GstCaps *ncaps = gst_caps_new_empty (); + + n = gst_caps_get_size (caps); + for (i = 0; i < n; i++) { + GstStructure *s = gst_caps_get_structure (caps, i); + + if (add_private && !gst_structure_has_name (s, "audio/x-private1-ac3")) { + GstStructure *ns = gst_structure_copy (s); + gst_structure_set_name (ns, "audio/x-private1-ac3"); + gst_caps_append_structure (ncaps, ns); + } else if (!add_private && + gst_structure_has_name (s, "audio/x-private1-ac3")) { + GstStructure *ns = gst_structure_copy (s); + gst_structure_set_name (ns, "audio/x-ac3"); + gst_caps_append_structure (ncaps, ns); + ns = gst_structure_copy (s); + gst_structure_set_name (ns, "audio/x-eac3"); + gst_caps_append_structure (ncaps, ns); + } else if (!add_private) { + gst_caps_append_structure (ncaps, gst_structure_copy (s)); + } + } + + if (add_private) { + gst_caps_append (caps, ncaps); + } else { + gst_caps_unref (caps); + caps = ncaps; + } + + return caps; +} + +static GstCaps * +gst_ac3_parse_get_sink_caps (GstBaseParse * parse, GstCaps * filter) +{ + GstCaps *peercaps, *templ; + GstCaps *res; + + templ = gst_pad_get_pad_template_caps (GST_BASE_PARSE_SINK_PAD (parse)); + if (filter) { + GstCaps *fcopy = gst_caps_copy (filter); + /* Remove the fields we convert */ + remove_fields (fcopy); + /* we do not ask downstream to handle x-private1-ac3 */ + fcopy = extend_caps (fcopy, FALSE); + peercaps = gst_pad_peer_query_caps (GST_BASE_PARSE_SRC_PAD (parse), fcopy); + gst_caps_unref (fcopy); + } else + peercaps = gst_pad_peer_query_caps (GST_BASE_PARSE_SRC_PAD (parse), NULL); + + if (peercaps) { + /* Remove the framed and alignment field. We can convert + * between different alignments. */ + peercaps = gst_caps_make_writable (peercaps); + remove_fields (peercaps); + /* also allow for x-private1-ac3 input */ + peercaps = extend_caps (peercaps, TRUE); + + res = gst_caps_intersect_full (peercaps, templ, GST_CAPS_INTERSECT_FIRST); + gst_caps_unref (peercaps); + gst_caps_unref (templ); + } else { + res = templ; + } + + if (filter) { + GstCaps *intersection; + + intersection = + gst_caps_intersect_full (filter, res, GST_CAPS_INTERSECT_FIRST); + gst_caps_unref (res); + res = intersection; + } + + return res; +} + +static gboolean +gst_ac3_parse_set_sink_caps (GstBaseParse * parse, GstCaps * caps) +{ + GstStructure *s; + GstAc3Parse *ac3parse = GST_AC3_PARSE (parse); + + s = gst_caps_get_structure (caps, 0); + if (gst_structure_has_name (s, "audio/x-private1-ac3")) { + gst_pad_set_chain_function (parse->sinkpad, gst_ac3_parse_chain_priv); + } else { + gst_pad_set_chain_function (parse->sinkpad, ac3parse->baseparse_chainfunc); + } + return TRUE; +} |