.PVA (mpeg-like fileformat used by MultiDec && WinTV) demuxer

slightly modified patch, original by Matteo Giani <matgiani@ctonet.it>


git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@7365 b3059339-0415-0410-9bf9-f77b7e298cf2

1 files changed, 412 insertions, 0 deletions

diff --git a/libmpdemux/demux_pva.c b/libmpdemux/demux_pva.c
new file mode 100644
index 0000000000..e07aac5b59
--- /dev/null
+++ b/libmpdemux/demux_pva.c
@@ -0,0 +1,412 @@
+/*
+ * demuxer for PVA files, such as the ones produced by software to manage DVB boards
+ * like the Hauppauge WinTV DVBs, for MPlayer.
+ *
+ * Uses info from the PVA file specifications found at
+ * 
+ * http://www.technotrend.de/download/av_format_v1.pdf
+ * 
+ * Known issue:
+ * - Does not seem to correctly demux files produced by MultiDec (on some channels).
+ *   They seem not to be correctly formatted. In fact, other DVB software which uses
+ *   the DVB board for playback plays them fine, but existing software which should
+ *   convert PVAs to MPEG-PS streams fails on them as well.
+ *   Feedback would be appreciated.
+ *
+ *
+ * written by Matteo Giani
+ */
+
+
+
+
+#include "config.h"
+#include "mp_msg.h"
+#include "help_mp.h"
+
+#include "stream.h"
+#include "demuxer.h"
+#include "stheader.h"
+
+#include "bswap.h"
+
+/*
+ * #defines below taken from PVA spec (see URL above)
+ */
+
+#define PVA_MAX_VIDEO_PACK_LEN 6*1024
+
+#define VIDEOSTREAM 0x01	
+#define MAINAUDIOSTREAM 0x02
+
+typedef struct {
+	unsigned long offset;
+	long size;
+	uint8_t type;
+	uint8_t is_packet_start;
+	uint64_t pts;
+} pva_payload_t;
+
+
+typedef struct {
+	float last_audio_pts;
+	float last_video_pts;
+	uint8_t just_synced;
+	uint8_t synced_stream_id;
+} pva_priv_t;
+
+
+int pva_sync(demuxer_t * demuxer)
+{
+	uint8_t buffer[5]={0,0,0,0,0};
+	int count;
+	pva_priv_t * priv = (pva_priv_t *) demuxer->priv;
+	
+	/* This is a hack. Since this function is called both for actual syncing and by
+	 * pva_check_file to check file type, we must check whether the priv structure has
+	 * already been allocated, otherwise we will dereference NULL and segfault.
+	 * So, if priv is NULL (not yet allocated) use a local variable, otherwise use priv->just_synced.
+	 * This field is in the priv structure so that pva_get_payload knows that pva_sync has already
+	 * read (part of) the PVA header. This way we can avoid to seek back and (hopefully) be able to read
+	 * from pipes and such.
+	 */
+	
+	uint8_t local_synced=0;
+	uint8_t * syncedptr;
+
+	syncedptr=(priv==NULL)?&local_synced:&priv->just_synced;
+
+	
+	for(count=0 ; count<PVA_MAX_VIDEO_PACK_LEN && !demuxer->stream->eof && !*syncedptr ; count++)
+	{
+		buffer[0]=buffer[1];
+		buffer[1]=buffer[2];
+		buffer[2]=buffer[3];
+		buffer[3]=buffer[4];
+		buffer[4]=stream_read_char(demuxer->stream);
+		/*
+		 * Check for a PVA packet beginning sequence: we check both the "AV" word at the 
+		 * very beginning and the "0x55" reserved byte (which is unused and set to 0x55 by spec)
+		 */
+		if(buffer[0]=='A' && buffer[1] == 'V' && buffer[4] == 0x55) *syncedptr=1;
+		//printf("demux_pva: pva_sync() current offset: %d\n",stream_tell(demuxer->stream));
+	}
+	if(*syncedptr)
+	{
+		if(priv!=NULL) priv->synced_stream_id=buffer[2];
+		return 1;
+	}
+	else
+	{
+		return 0;
+	}
+}
+
+int pva_check_file(demuxer_t * demuxer)
+{
+	uint8_t buffer[5]={0,0,0,0,0};
+	mp_msg(MSGT_DEMUX, MSGL_V, "Checking for PVA\n");
+	stream_read(demuxer->stream,buffer,5);
+	if(buffer[0]=='A' && buffer[1] == 'V' && buffer[4] == 0x55)
+	{
+		mp_msg(MSGT_DEMUX,MSGL_DBG2, "Success: PVA\n");
+		return 1;
+	}
+	else
+	{
+		mp_msg(MSGT_DEMUX,MSGL_DBG2, "Failed: PVA\n");
+		return 0;
+	}
+}
+
+demuxer_t * demux_open_pva (demuxer_t * demuxer)
+{
+	sh_video_t *sh_video = new_sh_video(demuxer,0);
+	sh_audio_t * sh_audio = new_sh_audio(demuxer,0);
+	pva_priv_t * priv;
+	unsigned char * buffer;
+
+		
+	
+	stream_reset(demuxer->stream);
+	stream_seek(demuxer->stream,0);
+	
+	
+
+	priv=malloc(sizeof(pva_priv_t));
+	
+	if(demuxer->stream->type!=STREAMTYPE_FILE) demuxer->seekable=0;
+	else demuxer->seekable=1;
+	
+	demuxer->priv=priv;
+	memset(demuxer->priv,0,sizeof(pva_priv_t));
+			
+	if(!pva_sync(demuxer))
+	{
+		mp_msg(MSGT_DEMUX,MSGL_ERR,"Not a PVA file.\n");
+		return NULL;
+	}
+
+	//printf("priv->just_synced %s after initial sync!\n",priv->just_synced?"set":"UNSET");
+	
+	demuxer->video->sh=sh_video;
+	demuxer->audio->sh=sh_audio;
+	mp_msg(MSGT_DEMUXER,MSGL_INFO,"Opened PVA demuxer...\n");
+	
+	/*
+	 * Audio and Video codecs:
+	 * the PVA spec only allows MPEG2 video and MPEG layer II audio. No need to check the formats then.
+	 * Moreover, there would be no way to do that since the PVA stream format has no fields to describe
+	 * the used codecs.
+	 */
+	
+	sh_video->format=0x10000002;
+	sh_video->ds=demuxer->video;
+		
+	sh_audio->format=0x50;
+	sh_audio->ds=demuxer->audio;
+
+	priv->last_video_pts=-1;
+	priv->last_audio_pts=-1;
+
+	return demuxer;
+}
+
+// 0 = EOF or no stream found
+// 1 = successfully read a packet
+int demux_pva_fill_buffer (demuxer_t * demux)
+{
+	uint8_t done=0;
+	demux_packet_t * dp;
+	pva_priv_t * priv=demux->priv;
+	pva_payload_t current_payload;
+
+	while(!done)
+	{
+		if(!pva_get_payload(demux,&current_payload)) return 0;
+		switch(current_payload.type)
+		{
+			case VIDEOSTREAM:
+				if(!current_payload.is_packet_start && priv->last_video_pts==-1)
+				{
+					/* We should only be here at the beginning of a stream, when we have
+					 * not yet encountered a valid Video PTS, or after a seek.
+					 * So, skip these starting packets in order not to deliver the
+					 * player a bogus PTS.
+					 */
+					done=0;
+				}
+				else
+				{
+					/*
+					 * In every other condition, we are delivering the payload. Set this
+					 * so that the following code knows whether to skip it or read it.
+					 */
+					done=1;
+				}
+				if(current_payload.is_packet_start)
+				{
+					priv->last_video_pts=((float)current_payload.pts)/90000;
+					//mp_msg(MSGT_DEMUXER,MSGL_DBG2,"demux_pva: Video PTS=%llu , delivered %f\n",current_payload.pts,priv->last_video_pts);
+				}
+				if(done)
+				{
+					dp=new_demux_packet(current_payload.size);
+					dp->pts=priv->last_video_pts;
+					stream_read(demux->stream,dp->buffer,current_payload.size);
+					ds_add_packet(demux->video,dp);
+				}
+				else
+				{
+					//printf("Skipping %u video bytes\n",current_payload.size);
+					stream_skip(demux->stream,current_payload.size);
+				}
+				break;
+			case MAINAUDIOSTREAM:
+				if(!current_payload.is_packet_start && priv->last_audio_pts==-1)
+				{
+					/* Same as above for invalid video PTS, just for audio. */
+					done=0;
+				}
+				else
+				{
+					done=1;
+				}
+				if(current_payload.is_packet_start)
+				{
+					priv->last_audio_pts=(float)current_payload.pts/90000;
+				}
+				if(done)
+				{
+					dp=new_demux_packet(current_payload.size);
+					dp->pts=priv->last_audio_pts;
+					stream_read(demux->stream,dp->buffer,current_payload.size);
+					ds_add_packet(demux->audio,dp);
+				}
+				else
+				{
+					stream_skip(demux->stream,current_payload.size);
+				}
+				break;
+		}
+	}
+	return 1;
+}
+
+int pva_get_payload(demuxer_t * d,pva_payload_t * payload)
+{
+	uint8_t flags,pes_head_len;
+	uint16_t pack_size;
+	long long next_offset,pva_payload_start;
+	unsigned char buffer[256];
+	demux_packet_t * dp; 	//hack to deliver the preBytes (see PVA doc)
+	pva_priv_t * priv=(pva_priv_t *) d->priv;
+
+	
+	if(d==NULL)
+	{
+		printf("demux_pva: pva_get_payload got passed a NULL pointer!\n");
+		return 0;
+	}
+
+	
+	if(d->stream->eof)
+	{
+		mp_msg(MSGT_DEMUX,MSGL_V,"demux_pva: pva_get_payload() detected stream->eof!!!\n");
+		return 0;
+	}
+
+	//printf("priv->just_synced %s\n",priv->just_synced?"SET":"UNSET");
+	if(!priv->just_synced)
+	{
+		if(stream_read_word(d->stream) != (('A'<<8)|'V'))
+		{
+			mp_msg(MSGT_DEMUX,MSGL_V,"demux_pva: pva_get_payload() missed a SyncWord at %ld!! Trying to sync...\n",stream_tell(d->stream));
+			if(!pva_sync(d)) return 0;
+		}
+	}
+	if(priv->just_synced)
+	{
+		payload->type=priv->synced_stream_id;
+		priv->just_synced=0;
+	}
+	else
+	{
+		payload->type=stream_read_char(d->stream);
+		stream_skip(d->stream,2); //counter and reserved
+	}
+	flags=stream_read_char(d->stream);
+	payload->is_packet_start=flags & 0x10;
+	pack_size=le2me_16(stream_read_word(d->stream));
+	mp_msg(MSGT_DEMUX,MSGL_DBG2,"demux_pva::pva_get_payload(): pack_size=%u field read at offset %lu\n",pack_size,stream_tell(d->stream)-2);
+	pva_payload_start=stream_tell(d->stream);
+	next_offset=pva_payload_start+pack_size;
+	if(!payload->is_packet_start)
+	{
+		payload->offset=stream_tell(d->stream);
+		payload->size=pack_size;
+	}
+	else
+	{	//here comes the good part...
+		switch(payload->type)
+		{
+			case VIDEOSTREAM:
+				payload->pts=le2me_32(stream_read_dword(d->stream));
+				//printf("Video PTS: %llu\n",payload->pts);
+				if((flags&0x03) && ((pva_priv_t *)d->priv)->last_video_pts!=-1)
+				{
+					dp=new_demux_packet(flags&0x03);
+					stream_read(d->stream,dp->buffer,flags & 0x03); //read PreBytes
+					dp->pts=((pva_priv_t *)d->priv)->last_video_pts;
+					ds_add_packet(d->video,dp);
+				}
+				else
+				{
+					stream_skip(d->stream,flags&0x03);
+				}
+
+				//now we are at real beginning of payload.
+				payload->offset=stream_tell(d->stream);
+				//size is pack_size minus PTS size minus padding size.
+				payload->size=pack_size - 4 - (flags & 0x03);
+				break;
+			case MAINAUDIOSTREAM:
+				stream_skip(d->stream,8); //FIXME properly parse PES header.
+				//assuming byte 8 is PES residual header length.
+				pes_head_len=stream_read_char(d->stream);
+				stream_read(d->stream,buffer,pes_head_len);
+				//we should now be on start of real payload.
+				//let's now parse the PTS...
+				if((buffer[0] & 0xf0)!=0x20)
+				{
+					mp_msg(MSGT_DEMUX,MSGL_ERR,"demux_pva: expected audio PTS but badly formatted... (read 0x%02X)\n",buffer[0]);
+					return;
+				}
+				payload->pts=0LL;
+				payload->pts|=((uint64_t)(buffer[0] & 0x0e) << 29);
+				payload->pts|=buffer[1]<<22;
+				payload->pts|=(buffer[2] & 0xfe) << 14;
+				payload->pts|=buffer[3]<<7;
+				payload->pts|=(buffer[4] & 0xfe) >> 1;
+				/*
+				 * PTS parsing is hopefully finished.
+				 * Let's now fill in offset and size.
+				 */
+				payload->pts=le2me_64(payload->pts);
+				payload->offset=stream_tell(d->stream);
+				payload->size=pack_size-stream_tell(d->stream)+pva_payload_start;
+				break;
+		}
+	}
+}
+
+int demux_seek_pva(demuxer_t * demuxer,float rel_seek_secs,int flags)
+{
+	int total_bitrate=0;
+	long dest_offset;
+	pva_priv_t * priv=demuxer->priv;
+	
+	total_bitrate=((sh_audio_t *)demuxer->audio->sh)->i_bps + ((sh_video_t *)demuxer->video->sh)->i_bps;
+
+	/*
+	 * Compute absolute offset inside the stream. Approximate total bitrate with sum of bitrates
+	 * reported by the audio and video codecs. The seek is not accurate because, just like
+	 * with MPEG streams, the bitrate is not constant. Moreover, we do not take into account
+	 * the overhead caused by PVA and PES headers.
+	 * If the calculated absolute offset is negative, seek to the beginning of the file.
+	 */
+	
+	dest_offset=stream_tell(demuxer->stream)+rel_seek_secs*total_bitrate;
+	if(dest_offset<0) dest_offset=0;
+	
+	stream_seek(demuxer->stream,dest_offset);
+
+	if(!pva_sync(demuxer))
+	{
+		mp_msg(MSGT_DEMUX,MSGL_V,"demux_pva: Couldn't seek!\n");
+		return 0;
+	}
+	
+	/*
+	 * Reset the PTS info inside the pva_priv_t structure. This way we don't deliver
+	 * data with the wrong PTSs (the ones we had before seeking).
+	 *
+	 */
+	
+	priv->last_video_pts=-1;
+	priv->last_audio_pts=-1;
+	
+	return 1;
+}
+
+
+
+void demux_close_pva(demuxer_t * demuxer)
+{
+	if(demuxer->priv)
+	{
+		free(demuxer->priv);
+		demuxer->priv=NULL;
+	}
+}
+