1 /*****************************************************************************
2 * mpegvideo.c: parse and packetize an MPEG1/2 video stream
3 *****************************************************************************
4 * Copyright (C) 2001-2006 the VideoLAN team
7 * Authors: Laurent Aimar <fenrir@via.ecp.fr>
8 * Eric Petit <titer@videolan.org>
9 * Gildas Bazin <gbazin@videolan.org>
10 * Jean-Paul Saman <jpsaman #_at_# m2x dot nl>
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
25 *****************************************************************************/
27 /*****************************************************************************
28 * Problem with this implementation:
30 * Although we should time-stamp each picture with a PTS, this isn't possible
31 * with the current implementation.
32 * The problem comes from the fact that for non-low-delay streams we can't
33 * calculate the PTS of pictures used as backward reference. Even the temporal
34 * reference number doesn't help here because all the pictures don't
35 * necessarily have the same duration (eg. 3:2 pulldown).
37 * However this doesn't really matter as far as the MPEG muxers are concerned
38 * because they allow having empty PTS fields. --gibalou
39 *****************************************************************************/
41 /*****************************************************************************
43 *****************************************************************************/
49 #include <vlc_common.h>
50 #include <vlc_plugin.h>
51 #include <vlc_block.h>
52 #include <vlc_codec.h>
53 #include <vlc_block_helper.h>
54 #include "../codec/cc.h"
55 #include "packetizer_helper.h"
57 #define SYNC_INTRAFRAME_TEXT N_("Sync on Intra Frame")
58 #define SYNC_INTRAFRAME_LONGTEXT N_("Normally the packetizer would " \
59 "sync on the next full frame. This flags instructs the packetizer " \
60 "to sync on the first Intra Frame found.")
62 /*****************************************************************************
64 *****************************************************************************/
65 static int Open ( vlc_object_t * );
66 static void Close( vlc_object_t * );
69 set_category( CAT_SOUT )
70 set_subcategory( SUBCAT_SOUT_PACKETIZER )
71 set_description( N_("MPEG-I/II video packetizer") )
72 set_shortname( N_("MPEG Video") )
73 set_capability( "packetizer", 50 )
74 set_callbacks( Open, Close )
76 add_bool( "packetizer-mpegvideo-sync-iframe", 0, NULL, SYNC_INTRAFRAME_TEXT,
77 SYNC_INTRAFRAME_LONGTEXT, true )
80 /*****************************************************************************
82 *****************************************************************************/
88 packetizer_t packetizer;
90 /* Sequence header and extension */
94 /* Current frame being built */
102 /* Sequence properties */
104 int i_frame_rate_base;
105 bool b_seq_progressive;
107 int i_aspect_ratio_info;
110 /* Picture properties */
113 int i_picture_structure;
114 int i_top_field_first;
115 int i_repeat_first_field;
116 int i_progressive_frame;
118 mtime_t i_interpolated_dts;
119 mtime_t i_last_ref_pts;
122 /* Number of pictures since last sequence header */
126 bool b_sync_on_intra_frame;
127 bool b_discontinuity;
137 static block_t *Packetize( decoder_t *, block_t ** );
138 static block_t *GetCc( decoder_t *p_dec, bool pb_present[4] );
140 static void PacketizeReset( void *p_private, bool b_broken );
141 static block_t *PacketizeParse( void *p_private, bool *pb_ts_used, block_t * );
142 static int PacketizeValidate( void *p_private, block_t * );
144 static block_t *ParseMPEGBlock( decoder_t *, block_t * );
146 static const uint8_t p_mp2v_startcode[3] = { 0x00, 0x00, 0x01 };
148 /*****************************************************************************
150 *****************************************************************************/
151 static int Open( vlc_object_t *p_this )
153 decoder_t *p_dec = (decoder_t*)p_this;
154 decoder_sys_t *p_sys;
156 if( p_dec->fmt_in.i_codec != VLC_FOURCC( 'm', 'p', 'g', '1' ) &&
157 p_dec->fmt_in.i_codec != VLC_FOURCC( 'm', 'p', 'g', '2' ) &&
158 p_dec->fmt_in.i_codec != VLC_FOURCC( 'm', 'p', 'g', 'v' ) )
163 es_format_Init( &p_dec->fmt_out, VIDEO_ES, VLC_FOURCC('m','p','g','v') );
164 p_dec->pf_packetize = Packetize;
165 p_dec->pf_get_cc = GetCc;
167 p_dec->p_sys = p_sys = malloc( sizeof( decoder_sys_t ) );
170 memset( p_dec->p_sys, 0, sizeof( decoder_sys_t ) );
173 packetizer_Init( &p_sys->packetizer,
174 p_mp2v_startcode, sizeof(p_mp2v_startcode),
176 PacketizeReset, PacketizeParse, PacketizeValidate, p_dec );
180 p_sys->p_frame = NULL;
181 p_sys->pp_last = &p_sys->p_frame;
182 p_sys->b_frame_slice = false;
184 p_sys->i_dts = p_sys->i_pts = 0;
186 p_sys->i_frame_rate = 1;
187 p_sys->i_frame_rate_base = 1;
188 p_sys->b_seq_progressive = true;
189 p_sys->b_low_delay = true;
190 p_sys->i_seq_old = 0;
192 p_sys->i_temporal_ref = 0;
193 p_sys->i_picture_type = 0;
194 p_sys->i_picture_structure = 0x03; /* frame */
195 p_sys->i_top_field_first = 0;
196 p_sys->i_repeat_first_field = 0;
197 p_sys->i_progressive_frame = 0;
200 p_sys->i_interpolated_dts = 0;
201 p_sys->i_last_ref_pts = 0;
202 p_sys->b_second_field = 0;
204 p_sys->b_discontinuity = false;
205 p_sys->b_sync_on_intra_frame = var_CreateGetBool( p_dec, "packetizer-mpegvideo-sync-iframe" );
206 if( p_sys->b_sync_on_intra_frame )
207 msg_Dbg( p_dec, "syncing on intra frame now" );
209 p_sys->b_cc_reset = false;
212 p_sys->i_cc_flags = 0;
213 cc_Init( &p_sys->cc );
218 /*****************************************************************************
220 *****************************************************************************/
221 static void Close( vlc_object_t *p_this )
223 decoder_t *p_dec = (decoder_t*)p_this;
224 decoder_sys_t *p_sys = p_dec->p_sys;
228 block_Release( p_sys->p_seq );
232 block_Release( p_sys->p_ext );
236 block_ChainRelease( p_sys->p_frame );
238 packetizer_Clean( &p_sys->packetizer );
240 var_Destroy( p_dec, "packetizer-mpegvideo-sync-iframe" );
245 /*****************************************************************************
247 *****************************************************************************/
248 static block_t *Packetize( decoder_t *p_dec, block_t **pp_block )
250 decoder_sys_t *p_sys = p_dec->p_sys;
252 return packetizer_Packetize( &p_sys->packetizer, pp_block );
255 /*****************************************************************************
257 *****************************************************************************/
258 static block_t *GetCc( decoder_t *p_dec, bool pb_present[4] )
260 decoder_sys_t *p_sys = p_dec->p_sys;
264 for( i = 0; i < 4; i++ )
265 pb_present[i] = p_sys->cc.pb_present[i];
267 if( p_sys->cc.i_data <= 0 )
270 p_cc = block_New( p_dec, p_sys->cc.i_data);
273 memcpy( p_cc->p_buffer, p_sys->cc.p_data, p_sys->cc.i_data );
275 p_cc->i_pts = p_sys->cc.b_reorder ? p_sys->i_cc_pts : p_sys->i_cc_dts;
276 p_cc->i_flags = ( p_sys->cc.b_reorder ? p_sys->i_cc_flags : BLOCK_FLAG_TYPE_P ) & ( BLOCK_FLAG_TYPE_I|BLOCK_FLAG_TYPE_P|BLOCK_FLAG_TYPE_B);
278 cc_Flush( &p_sys->cc );
282 /*****************************************************************************
284 *****************************************************************************/
285 static void PacketizeReset( void *p_private, bool b_broken )
287 decoder_t *p_dec = p_private;
288 decoder_sys_t *p_sys = p_dec->p_sys;
292 p_sys->b_discontinuity = true;
294 block_ChainRelease( p_sys->p_frame );
295 p_sys->p_frame = NULL;
296 p_sys->pp_last = &p_sys->p_frame;
297 p_sys->b_frame_slice = false;
301 p_sys->i_interpolated_dts = 0;
302 p_sys->i_last_ref_pts = 0;
305 static block_t *PacketizeParse( void *p_private, bool *pb_ts_used, block_t *p_block )
307 decoder_t *p_dec = p_private;
309 /* Check if we have a picture start code */
310 *pb_ts_used = p_block->i_buffer >= 4 && p_block->p_buffer[3] == 0x00;
312 return ParseMPEGBlock( p_dec, p_block );
316 static int PacketizeValidate( void *p_private, block_t *p_au )
318 decoder_t *p_dec = p_private;
319 decoder_sys_t *p_sys = p_dec->p_sys;
321 /* If a discontinuity has been encountered, then wait till
322 * the next Intra frame before continuing with packetizing */
323 if( p_sys->b_discontinuity &&
324 p_sys->b_sync_on_intra_frame )
326 if( (p_au->i_flags & BLOCK_FLAG_TYPE_I) == 0 )
328 msg_Dbg( p_dec, "waiting on intra frame" );
331 msg_Dbg( p_dec, "synced on intra frame" );
332 p_sys->b_discontinuity = false;
333 p_au->i_flags |= BLOCK_FLAG_DISCONTINUITY;
336 /* We've just started the stream, wait for the first PTS.
337 * We discard here so we can still get the sequence header. */
338 if( p_sys->i_dts <= 0 && p_sys->i_pts <= 0 &&
339 p_sys->i_interpolated_dts <= 0 )
341 msg_Dbg( p_dec, "need a starting pts/dts" );
345 /* When starting the stream we can have the first frame with
346 * a null DTS (i_interpolated_pts is initialized to 0) */
348 p_au->i_dts = p_au->i_pts;
352 /*****************************************************************************
353 * ParseMPEGBlock: Re-assemble fragments into a block containing a picture
354 *****************************************************************************/
355 static block_t *ParseMPEGBlock( decoder_t *p_dec, block_t *p_frag )
357 decoder_sys_t *p_sys = p_dec->p_sys;
358 block_t *p_pic = NULL;
361 * Check if previous picture is finished
363 if( ( p_sys->b_frame_slice &&
364 (p_frag->p_buffer[3] == 0x00 || p_frag->p_buffer[3] > 0xaf) ) &&
365 p_sys->p_seq == NULL )
367 /* We have a picture but without a sequence header we can't
369 msg_Dbg( p_dec, "waiting for sequence start" );
370 if( p_sys->p_frame ) block_ChainRelease( p_sys->p_frame );
371 p_sys->p_frame = NULL;
372 p_sys->pp_last = &p_sys->p_frame;
373 p_sys->b_frame_slice = false;
376 else if( p_sys->b_frame_slice &&
377 (p_frag->p_buffer[3] == 0x00 || p_frag->p_buffer[3] > 0xaf) )
379 const bool b_eos = p_frag->p_buffer[3] == 0xb7;
385 block_ChainLastAppend( &p_sys->pp_last, p_frag );
389 p_pic = block_ChainGather( p_sys->p_frame );
392 p_pic->i_flags |= BLOCK_FLAG_END_OF_SEQUENCE;
394 i_duration = (mtime_t)( 1000000 * p_sys->i_frame_rate_base /
395 p_sys->i_frame_rate );
397 if( !p_sys->b_seq_progressive && p_sys->i_picture_structure != 0x03 )
402 if( p_sys->b_seq_progressive )
404 if( p_sys->i_top_field_first == 0 &&
405 p_sys->i_repeat_first_field == 1 )
409 else if( p_sys->i_top_field_first == 1 &&
410 p_sys->i_repeat_first_field == 1 )
417 if( p_sys->i_picture_structure == 0x03 )
419 if( p_sys->i_progressive_frame && p_sys->i_repeat_first_field )
421 i_duration += i_duration / 2;
426 if( p_sys->b_low_delay || p_sys->i_picture_type == 0x03 )
428 /* Trivial case (DTS == PTS) */
429 /* Correct interpolated dts when we receive a new pts/dts */
430 if( p_sys->i_pts > 0 ) p_sys->i_interpolated_dts = p_sys->i_pts;
431 if( p_sys->i_dts > 0 ) p_sys->i_interpolated_dts = p_sys->i_dts;
435 /* Correct interpolated dts when we receive a new pts/dts */
436 if( p_sys->i_last_ref_pts > 0 && !p_sys->b_second_field )
437 p_sys->i_interpolated_dts = p_sys->i_last_ref_pts;
438 if( p_sys->i_dts > 0 ) p_sys->i_interpolated_dts = p_sys->i_dts;
440 if( !p_sys->b_second_field )
441 p_sys->i_last_ref_pts = p_sys->i_pts;
444 p_pic->i_dts = p_sys->i_interpolated_dts;
445 p_sys->i_interpolated_dts += i_duration;
447 /* Set PTS only if we have a B frame or if it comes from the stream */
448 if( p_sys->i_pts > 0 )
450 p_pic->i_pts = p_sys->i_pts;
452 else if( p_sys->i_picture_type == 0x03 )
454 p_pic->i_pts = p_pic->i_dts;
461 switch ( p_sys->i_picture_type )
464 p_pic->i_flags |= BLOCK_FLAG_TYPE_I;
467 p_pic->i_flags |= BLOCK_FLAG_TYPE_P;
470 p_pic->i_flags |= BLOCK_FLAG_TYPE_B;
474 p_pic->i_length = p_sys->i_interpolated_dts - p_pic->i_dts;
477 msg_Dbg( p_dec, "pic: type=%d dts=%"PRId64" pts-dts=%"PRId64,
478 p_sys->i_picture_type, p_pic->i_dts, p_pic->i_pts - p_pic->i_dts);
482 p_sys->p_frame = NULL;
483 p_sys->pp_last = &p_sys->p_frame;
484 p_sys->b_frame_slice = false;
486 if( p_sys->i_picture_structure != 0x03 )
488 p_sys->b_second_field = !p_sys->b_second_field;
492 p_sys->b_second_field = 0;
496 p_sys->b_cc_reset = true;
497 p_sys->i_cc_pts = p_pic->i_pts;
498 p_sys->i_cc_dts = p_pic->i_dts;
499 p_sys->i_cc_flags = p_pic->i_flags;
502 if( !p_pic && p_sys->b_cc_reset )
504 p_sys->b_cc_reset = false;
505 cc_Flush( &p_sys->cc );
511 * Check info of current fragment
513 if( p_frag->p_buffer[3] == 0xb8 )
515 /* Group start code */
517 p_sys->i_seq_old > p_sys->i_frame_rate/p_sys->i_frame_rate_base )
519 /* Usefull for mpeg1: repeat sequence header every second */
520 block_ChainLastAppend( &p_sys->pp_last, block_Duplicate( p_sys->p_seq ) );
523 block_ChainLastAppend( &p_sys->pp_last, block_Duplicate( p_sys->p_ext ) );
526 p_sys->i_seq_old = 0;
529 else if( p_frag->p_buffer[3] == 0xb3 && p_frag->i_buffer >= 8 )
531 /* Sequence header code */
532 static const int code_to_frame_rate[16][2] =
534 { 1, 1 }, /* invalid */
535 { 24000, 1001 }, { 24, 1 }, { 25, 1 }, { 30000, 1001 },
536 { 30, 1 }, { 50, 1 }, { 60000, 1001 }, { 60, 1 },
537 /* Unofficial 15fps from Xing*/
539 /* Unofficial economy rates from libmpeg3 */
540 { 5, 1001 }, { 10, 1001 }, { 12, 1001 }, { 15, 1001 },
541 { 1, 1 }, { 1, 1 } /* invalid */
544 if( p_sys->p_seq ) block_Release( p_sys->p_seq );
545 if( p_sys->p_ext ) block_Release( p_sys->p_ext );
547 p_sys->p_seq = block_Duplicate( p_frag );
548 p_sys->i_seq_old = 0;
551 p_dec->fmt_out.video.i_width =
552 ( p_frag->p_buffer[4] << 4)|(p_frag->p_buffer[5] >> 4 );
553 p_dec->fmt_out.video.i_height =
554 ( (p_frag->p_buffer[5]&0x0f) << 8 )|p_frag->p_buffer[6];
555 p_sys->i_aspect_ratio_info = p_frag->p_buffer[7] >> 4;
557 /* TODO: MPEG1 aspect ratio */
559 p_sys->i_frame_rate = code_to_frame_rate[p_frag->p_buffer[7]&0x0f][0];
560 p_sys->i_frame_rate_base =
561 code_to_frame_rate[p_frag->p_buffer[7]&0x0f][1];
563 p_dec->fmt_out.video.i_frame_rate = p_sys->i_frame_rate;
564 p_dec->fmt_out.video.i_frame_rate_base = p_sys->i_frame_rate_base;
566 p_sys->b_seq_progressive = true;
567 p_sys->b_low_delay = true;
569 if ( !p_sys->b_inited )
571 msg_Dbg( p_dec, "size %dx%d fps=%.3f",
572 p_dec->fmt_out.video.i_width, p_dec->fmt_out.video.i_height,
573 p_sys->i_frame_rate / (float)p_sys->i_frame_rate_base );
577 else if( p_frag->p_buffer[3] == 0xb5 )
579 int i_type = p_frag->p_buffer[4] >> 4;
581 /* Extension start code */
585 static const int mpeg2_aspect[16][2] =
587 {0,1}, {1,1}, {4,3}, {16,9}, {221,100},
588 {0,1}, {0,1}, {0,1}, {0,1}, {0,1}, {0,1}, {0,1}, {0,1}, {0,1},
593 /* sequence extension */
594 if( p_sys->p_ext) block_Release( p_sys->p_ext );
595 p_sys->p_ext = block_Duplicate( p_frag );
597 if( p_frag->i_buffer >= 10 )
599 p_sys->b_seq_progressive =
600 p_frag->p_buffer[5]&0x08 ? true : false;
602 p_frag->p_buffer[9]&0x80 ? true : false;
605 /* Do not set aspect ratio : in case we're transcoding,
606 * transcode will take our fmt_out as a fmt_in to libmpeg2.
607 * libmpeg2.c will then believe that the user has requested
608 * a specific aspect ratio, which she hasn't. Thus in case
609 * of aspect ratio change, we're screwed. --Meuuh
612 p_dec->fmt_out.video.i_aspect =
613 mpeg2_aspect[p_sys->i_aspect_ratio_info][0] *
615 mpeg2_aspect[p_sys->i_aspect_ratio_info][1];
619 else if( i_type == 0x08 )
621 /* picture extension */
622 p_sys->i_picture_structure = p_frag->p_buffer[6]&0x03;
623 p_sys->i_top_field_first = p_frag->p_buffer[7] >> 7;
624 p_sys->i_repeat_first_field= (p_frag->p_buffer[7]>>1)&0x01;
625 p_sys->i_progressive_frame = p_frag->p_buffer[8] >> 7;
628 else if( p_frag->p_buffer[3] == 0xb2 && p_frag->i_buffer > 4 )
630 cc_Extract( &p_sys->cc, &p_frag->p_buffer[4], p_frag->i_buffer - 4 );
632 else if( p_frag->p_buffer[3] == 0x00 )
634 /* Picture start code */
637 if( p_frag->i_buffer >= 6 )
639 p_sys->i_temporal_ref =
640 ( p_frag->p_buffer[4] << 2 )|(p_frag->p_buffer[5] >> 6);
641 p_sys->i_picture_type = ( p_frag->p_buffer[5] >> 3 ) & 0x03;
644 p_sys->i_dts = p_frag->i_dts;
645 p_sys->i_pts = p_frag->i_pts;
647 else if( p_frag->p_buffer[3] >= 0x01 && p_frag->p_buffer[3] <= 0xaf )
649 /* Slice start code */
650 p_sys->b_frame_slice = true;
653 /* Append the block */
654 block_ChainLastAppend( &p_sys->pp_last, p_frag );