+++ /dev/null
-/*****************************************************************************
- * packet.c : helper for legacy audio output plugins
- *****************************************************************************
- * Copyright (C) 2002-2012 VLC authors and VideoLAN
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU Lesser General Public License as published by
- * the Free Software Foundation; either version 2.1 of the License, or
- * (at your option) any later version.
- *
- * This program 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 Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with this program; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
- *****************************************************************************/
-
-#ifdef HAVE_CONFIG_H
-# include <config.h>
-#endif
-#include <limits.h>
-#include <assert.h>
-#include <vlc_common.h>
-#include <vlc_aout.h>
-
-/**
- * Initializes the members of a FIFO.
- */
-static void aout_FifoInit( aout_fifo_t *p_fifo, uint32_t i_rate )
-{
- assert( i_rate != 0);
- p_fifo->p_first = NULL;
- p_fifo->pp_last = &p_fifo->p_first;
- date_Init( &p_fifo->end_date, i_rate, 1 );
- date_Set( &p_fifo->end_date, VLC_TS_INVALID );
-}
-
-/**
- * Pushes a packet into the FIFO.
- */
-static void aout_FifoPush( aout_fifo_t * p_fifo, block_t * p_buffer )
-{
- *p_fifo->pp_last = p_buffer;
- p_fifo->pp_last = &p_buffer->p_next;
- *p_fifo->pp_last = NULL;
- /* Enforce the continuity of the stream. */
- if( date_Get( &p_fifo->end_date ) != VLC_TS_INVALID )
- {
- p_buffer->i_pts = date_Get( &p_fifo->end_date );
- p_buffer->i_length = date_Increment( &p_fifo->end_date,
- p_buffer->i_nb_samples );
- p_buffer->i_length -= p_buffer->i_pts;
- }
- else
- {
- date_Set( &p_fifo->end_date, p_buffer->i_pts + p_buffer->i_length );
- }
-}
-
-/**
- * Trashes all buffers.
- */
-static void aout_FifoReset( aout_fifo_t * p_fifo )
-{
- block_t * p_buffer;
-
- date_Set( &p_fifo->end_date, VLC_TS_INVALID );
- p_buffer = p_fifo->p_first;
- while ( p_buffer != NULL )
- {
- block_t * p_next = p_buffer->p_next;
- block_Release( p_buffer );
- p_buffer = p_next;
- }
- p_fifo->p_first = NULL;
- p_fifo->pp_last = &p_fifo->p_first;
-}
-
-/**
- * Move forwards or backwards all dates in the FIFO.
- */
-static void aout_FifoMoveDates( aout_fifo_t *fifo, mtime_t difference )
-{
- if( date_Get( &fifo->end_date ) == VLC_TS_INVALID )
- {
- assert( fifo->p_first == NULL );
- return;
- }
-
- date_Move( &fifo->end_date, difference );
- for( block_t *block = fifo->p_first; block != NULL; block = block->p_next )
- block->i_pts += difference;
-}
-
-/**
- * Gets the next buffer out of the FIFO
- */
-static block_t *aout_FifoPop( aout_fifo_t * p_fifo )
-{
- block_t *p_buffer = p_fifo->p_first;
- if( p_buffer != NULL )
- {
- p_fifo->p_first = p_buffer->p_next;
- if( p_fifo->p_first == NULL )
- p_fifo->pp_last = &p_fifo->p_first;
- }
- return p_buffer;
-}
-
-/**
- * Destroys a FIFO and its buffers
- */
-static void aout_FifoDestroy( aout_fifo_t * p_fifo )
-{
- block_t * p_buffer;
-
- p_buffer = p_fifo->p_first;
- while ( p_buffer != NULL )
- {
- block_t * p_next = p_buffer->p_next;
- block_Release( p_buffer );
- p_buffer = p_next;
- }
-
- p_fifo->p_first = NULL;
- p_fifo->pp_last = &p_fifo->p_first;
-}
-
-static inline aout_packet_t *aout_packet (audio_output_t *aout)
-{
- return (aout_packet_t *)(aout->sys);
-}
-
-void aout_PacketInit (audio_output_t *aout, aout_packet_t *p, unsigned samples,
- const audio_sample_format_t *fmt)
-{
- assert (p == aout_packet (aout));
-
- vlc_mutex_init (&p->lock);
- p->format = *fmt;
- aout_FormatPrepare (&p->format);
- aout_FifoInit (&p->partial, p->format.i_rate);
- aout_FifoInit (&p->fifo, p->format.i_rate);
- p->pause_date = VLC_TS_INVALID;
- p->samples = samples;
- p->starving = true;
-}
-
-void aout_PacketDestroy (audio_output_t *aout)
-{
- aout_packet_t *p = aout_packet (aout);
-
- aout_FifoDestroy (&p->partial);
- aout_FifoDestroy (&p->fifo);
- vlc_mutex_destroy (&p->lock);
-}
-
-int aout_PacketTimeGet (audio_output_t *aout, mtime_t *restrict delay)
-{
- aout_packet_t *p = aout_packet (aout);
- mtime_t time_report;
-
- /* Problem: This measurement is imprecise and prone to jitter.
- * Solution: Do not use aout_Packet...(). */
- vlc_mutex_lock (&p->lock);
- time_report = date_Get (&p->fifo.end_date);
- vlc_mutex_unlock (&p->lock);
-
- if (time_report == VLC_TS_INVALID)
- return -1;
- *delay = time_report - mdate ();
- return 0;
-}
-
-static block_t *aout_OutputSlice (audio_output_t *);
-
-void aout_PacketPlay (audio_output_t *aout, block_t *block)
-{
- aout_packet_t *p = aout_packet (aout);
-
- vlc_mutex_lock (&p->lock);
- aout_FifoPush (&p->partial, block);
- while ((block = aout_OutputSlice (aout)) != NULL)
- aout_FifoPush (&p->fifo, block);
- vlc_mutex_unlock (&p->lock);
-}
-
-void aout_PacketFlush (audio_output_t *aout, bool drain)
-{
- aout_packet_t *p = aout_packet (aout);
-
- vlc_mutex_lock (&p->lock);
- if (drain)
- {
- mtime_t pts = date_Get (&p->fifo.end_date);
- vlc_mutex_unlock (&p->lock);
- if (pts != VLC_TS_INVALID)
- mwait (pts);
- }
- else
- {
- aout_FifoReset (&p->partial);
- aout_FifoReset (&p->fifo);
- vlc_mutex_unlock (&p->lock);
- }
-}
-
-
-/**
- * Rearranges audio blocks in correct number of samples.
- * @note (FIXME) This is left here for historical reasons. It belongs in the
- * output code. Besides, this operation should be avoided if possible.
- */
-static block_t *aout_OutputSlice (audio_output_t *p_aout)
-{
- aout_packet_t *p = aout_packet (p_aout);
- aout_fifo_t *p_fifo = &p->partial;
- const unsigned samples = p->samples;
- assert( samples > 0 );
-
- /* Retrieve the date of the next buffer. */
- date_t exact_start_date = p->fifo.end_date;
- mtime_t start_date = date_Get( &exact_start_date );
-
- /* Check if there is enough data to slice a new buffer. */
- block_t *p_buffer = p_fifo->p_first;
- if( p_buffer == NULL )
- return NULL;
-
- /* Find the earliest start date available. */
- if ( start_date == VLC_TS_INVALID )
- {
- start_date = p_buffer->i_pts;
- date_Set( &exact_start_date, start_date );
- }
- /* Compute the end date for the new buffer. */
- mtime_t end_date = date_Increment( &exact_start_date, samples );
-
- /* Check that we have enough samples (TODO merge with next loop). */
- for( unsigned available = 0; available < samples; )
- {
- p_buffer = p_buffer->p_next;
- if( p_buffer == NULL )
- return NULL;
-
- available += p_buffer->i_nb_samples;
- }
-
- if( AOUT_FMT_LINEAR( &p->format ) )
- {
- const unsigned framesize = p->format.i_bytes_per_frame;
- /* Build packet with adequate number of samples */
- unsigned needed = samples * framesize;
-
- p_buffer = block_Alloc( needed );
- if( unlikely(p_buffer == NULL) )
- /* XXX: should free input buffers */
- return NULL;
- p_buffer->i_nb_samples = samples;
-
- for( uint8_t *p_out = p_buffer->p_buffer; needed > 0; )
- {
- block_t *p_inbuf = p_fifo->p_first;
- if( unlikely(p_inbuf == NULL) )
- {
- msg_Err( p_aout, "packetization error" );
- memset( p_out, 0, needed );
- break;
- }
-
- const uint8_t *p_in = p_inbuf->p_buffer;
- size_t avail = p_inbuf->i_nb_samples * framesize;
- if( avail > needed )
- {
- memcpy( p_out, p_in, needed );
- p_fifo->p_first->p_buffer += needed;
- p_fifo->p_first->i_buffer -= needed;
- needed /= framesize;
- p_fifo->p_first->i_nb_samples -= needed;
-
- mtime_t t = needed * CLOCK_FREQ / p->format.i_rate;
- p_fifo->p_first->i_pts += t;
- p_fifo->p_first->i_length -= t;
- break;
- }
-
- memcpy( p_out, p_in, avail );
- needed -= avail;
- p_out += avail;
- /* Next buffer */
- block_Release( aout_FifoPop( p_fifo ) );
- }
- }
- else
- p_buffer = aout_FifoPop( p_fifo );
-
- p_buffer->i_pts = start_date;
- p_buffer->i_length = end_date - start_date;
-
- return p_buffer;
-}
-
-/**
- * Dequeues the next audio packet (a.k.a. audio fragment).
- * The audio output plugin must first call aout_PacketPlay() to queue the
- * decoded audio samples. Typically, audio_output_t.play is set to, or calls
- * aout_PacketPlay().
- * @note This function is considered legacy. Please do not use this function in
- * new audio output plugins.
- * @param p_aout audio output instance
- * @param start_date expected PTS of the audio packet
- */
-block_t *aout_PacketNext (audio_output_t *p_aout, mtime_t start_date)
-{
- aout_packet_t *p = aout_packet (p_aout);
- aout_fifo_t *p_fifo = &p->fifo;
- block_t *p_buffer;
- const bool b_can_sleek = !AOUT_FMT_LINEAR(&p->format);
- const mtime_t now = mdate ();
- const mtime_t threshold =
- (b_can_sleek ? start_date : now) - AOUT_MAX_PTS_DELAY;
-
- vlc_mutex_lock( &p->lock );
- if( p->pause_date != VLC_TS_INVALID )
- goto out; /* paused: do not dequeue buffers */
-
- for (;;)
- {
- p_buffer = p_fifo->p_first;
- if (p_buffer == NULL)
- goto out; /* nothing to play */
-
- if (p_buffer->i_pts >= threshold)
- break;
-
- /* Drop the audio sample if the audio output is really late.
- * In the case of b_can_sleek, we don't use a resampler so we need to
- * be a lot more severe. */
- msg_Dbg (p_aout, "audio output is too slow (%"PRId64" us): "
- " trashing %"PRId64" us", threshold - p_buffer->i_pts,
- p_buffer->i_length);
- block_Release (aout_FifoPop (p_fifo));
- }
-
- mtime_t delta = start_date - p_buffer->i_pts;
- /* This assumes that all buffers have the same duration. This is true
- * since aout_PacketPlay() (aout_OutputSlice()) is used. */
- if (0 >= delta + p_buffer->i_length)
- {
- if (!p->starving)
- {
- msg_Dbg (p_aout, "audio output is starving (%"PRId64"), "
- "playing silence", delta);
- p->starving = true;
- }
- goto out; /* nothing to play _yet_ */
- }
-
- p->starving = false;
- p_buffer = aout_FifoPop( p_fifo );
-
- if (!b_can_sleek
- && (delta < -AOUT_MAX_PTS_ADVANCE || AOUT_MAX_PTS_DELAY < delta))
- {
- msg_Warn (p_aout, "audio output out of sync, "
- "adjusting dates (%"PRId64" us)", delta);
- aout_FifoMoveDates (&p->partial, delta);
- aout_FifoMoveDates (p_fifo, delta);
- }
- vlc_mutex_unlock( &p->lock );
- return p_buffer;
-out:
- vlc_mutex_unlock( &p->lock );
- return NULL;
-}
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