Start a DVD LPCM encoder.

diff --git a/modules/codec/lpcm.c b/modules/codec/lpcm.c
index 5980e9dd0b44db8aa45ecc026467ae91481b6048..01cbbbc6a63e81f9a209848339b45c2e3c51e78f 100644 (file)
--- a/modules/codec/lpcm.c
+++ b/modules/codec/lpcm.c
@@ -45,6 +45,12 @@ static int  OpenDecoder   ( vlc_object_t * );
 static int  OpenPacketizer( vlc_object_t * );
 static void CloseCommon   ( vlc_object_t * );
 
+#ifdef ENABLE_SOUT
+static int  OpenEncoder   ( vlc_object_t * );
+static void CloseEncoder  ( vlc_object_t * );
+static block_t *EncoderEncode( encoder_t *, aout_buffer_t * );
+#endif
+
 vlc_module_begin ()
 
     set_category( CAT_INPUT )
@@ -58,6 +64,12 @@ vlc_module_begin ()
     set_capability( "packetizer", 100 )
     set_callbacks( OpenPacketizer, CloseCommon )
 
+    add_submodule ()
+    set_description( N_("Linear PCM audio encoder") )
+    set_capability( "encoder", 100 )
+    set_callbacks( OpenEncoder, CloseEncoder )
+    add_shortcut( "lpcm" )
+
 vlc_module_end ()
 
 
@@ -79,17 +91,30 @@ struct decoder_sys_t
     int      i_type;
 };
 
+struct encoder_sys_t
+{
+    int     i_channels;
+    int     i_rate;
+
+    int     i_frame_samples;
+    uint8_t *p_buffer;
+    int     i_buffer_used;
+    int     i_frame_num;
+};
+
 /*
  * LPCM DVD header :
- * - frame number (8 bits)
- * - unknown (16 bits) == 0x0003 ?
- * - unknown (4 bits)
- * - current frame (4 bits)
- * - unknown (2 bits)
- * - frequency (2 bits) 0 == 48 kHz, 1 == 32 kHz, 2 == ?, 3 == ?
- * - unknown (1 bit)
+ * - number of frames in this packet (8 bits)
+ * - first access unit (16 bits) == 0x0003 ?
+ * - emphasis (1 bit)
+ * - mute (1 bit)
+ * - reserved (1 bit)
+ * - current frame (5 bits)
+ * - quantisation (2 bits) 0 == 16bps, 1 == 20bps, 2 == 24bps, 3 == illegal
+ * - frequency (2 bits) 0 == 48 kHz, 1 == 96 kHz, 2 == 44.1 kHz, 3 == 32 kHz
+ * - reserved (1 bit)
  * - number of channels - 1 (3 bits) 1 == 2 channels
- * - start code (8 bits) == 0x80
+ * - dynamic range (8 bits) 0x80 == neutral
  *
  * LPCM DVD-A header (http://dvd-audio.sourceforge.net/spec/aob.shtml)
  * - continuity counter (8 bits, clipped to 0x00-0x1f)
@@ -397,6 +422,139 @@ static void CloseCommon( vlc_object_t *p_this )
     free( p_dec->p_sys );
 }
 
+/*****************************************************************************
+ * OpenEncoder:
+ *****************************************************************************/
+static int OpenEncoder( vlc_object_t *p_this )
+{
+    encoder_t *p_enc = (encoder_t *)p_this;
+    encoder_sys_t *p_sys;
+
+    if( p_enc->fmt_out.i_codec != VLC_CODEC_DVD_LPCM ||
+        ( p_enc->fmt_in.audio.i_rate != 48000 &&
+          p_enc->fmt_in.audio.i_rate != 96000 &&
+          p_enc->fmt_in.audio.i_rate != 44100 &&
+          p_enc->fmt_in.audio.i_rate != 32000 ) ||
+       p_enc->fmt_in.audio.i_channels > 8 )
+    {
+        return VLC_EGENERIC;
+    }
+
+    /* Allocate the memory needed to store the encoder's structure */
+    if( ( p_enc->p_sys = p_sys =
+          (encoder_sys_t *)malloc(sizeof(encoder_sys_t)) ) == NULL )
+        return VLC_ENOMEM;
+
+    p_enc->pf_encode_audio = EncoderEncode;
+    p_enc->fmt_in.i_codec = p_enc->fmt_out.i_codec;
+
+    p_enc->fmt_in.audio.i_bitspersample = 16;
+    p_enc->fmt_in.i_codec = VLC_CODEC_S16B;
+
+    p_enc->fmt_out.i_bitrate =
+        p_enc->fmt_in.audio.i_channels *
+        p_enc->fmt_in.audio.i_rate *
+        p_enc->fmt_in.audio.i_bitspersample;
+    
+    p_sys->i_channels = p_enc->fmt_in.audio.i_channels;
+    p_sys->i_rate = p_enc->fmt_in.audio.i_rate;
+    
+    /* In DVD LCPM, a frame is always 150 PTS ticks. */
+    p_sys->i_frame_samples = p_enc->fmt_in.audio.i_rate * 150 / 90000;
+    p_sys->p_buffer = (uint8_t *)malloc(
+        p_sys->i_frame_samples *
+        p_enc->fmt_in.audio.i_channels *
+        p_enc->fmt_in.audio.i_bitspersample);
+    p_sys->i_buffer_used = 0;
+    p_sys->i_frame_num = 0;
+
+    return VLC_SUCCESS;
+}
+
+/*****************************************************************************
+ * CloseEncoder
+ *****************************************************************************/
+static void CloseEncoder ( vlc_object_t *p_this )
+{
+    VLC_UNUSED(p_this);
+}
+
+/*****************************************************************************
+ * EncoderEncode:
+ *****************************************************************************/
+static block_t *EncoderEncode( encoder_t *p_enc, aout_buffer_t *p_aout_buf )
+{
+    encoder_sys_t *p_sys = p_enc->p_sys;
+    block_t *p_block = NULL;
+
+    if( !p_aout_buf || !p_aout_buf->i_buffer ) return NULL;
+
+    const int i_num_frames = ( p_sys->i_buffer_used + p_aout_buf->i_nb_samples ) /
+        p_sys->i_frame_samples;
+    const int i_leftover_samples = ( p_sys->i_buffer_used + p_aout_buf->i_nb_samples ) %
+        p_sys->i_frame_samples;
+    const int i_frame_size = p_sys->i_frame_samples * p_sys->i_channels * 2 + LPCM_VOB_HEADER_LEN;
+
+    p_block = block_New( p_enc, i_num_frames * i_frame_size );
+    if( !p_block )
+        return NULL;
+
+    uint8_t i_freq_code = 0;
+
+    switch( p_sys->i_rate ) {
+    case 48000:
+        i_freq_code = 0;
+        break;
+    case 96000:
+        i_freq_code = 1;
+        break;
+    case 44100:
+        i_freq_code = 2;
+        break;
+    case 32000:
+        i_freq_code = 3;
+        break;
+    }
+
+    int i_bytes_consumed = 0;
+
+    for ( int i = 0; i < i_num_frames; ++i )
+    {
+        uint8_t *frame = (uint8_t *)p_block->p_buffer + i * i_frame_size;
+        frame[0] = 1;  /* one frame in packet */
+        frame[1] = 0;
+        frame[2] = 0;  /* no first access unit */
+        frame[3] = (p_sys->i_frame_num + i) & 0x1f;  /* no emphasis, no mute */
+        frame[4] = (i_freq_code << 4) | (p_sys->i_channels - 1);
+        frame[5] = 0x80;  /* neutral dynamic range */
+
+        const int i_consume_samples = p_sys->i_frame_samples - p_sys->i_buffer_used;
+        const int i_kept_bytes = p_sys->i_buffer_used * p_sys->i_channels * 2;
+        const int i_consume_bytes = i_consume_samples * p_sys->i_channels * 2;
+
+        memcpy( frame + 6, p_sys->p_buffer, i_kept_bytes );
+        memcpy( frame + 6 + i_kept_bytes, p_aout_buf->p_buffer + i_bytes_consumed, i_consume_bytes );
+     
+        p_sys->i_frame_num++;
+        p_sys->i_buffer_used = 0;
+        i_bytes_consumed += i_consume_bytes;
+    }
+
+    memcpy( p_sys->p_buffer,
+            p_aout_buf->p_buffer + i_bytes_consumed,
+            i_leftover_samples * p_sys->i_channels * 2 );
+    p_sys->i_buffer_used = i_leftover_samples;
+
+    /* 
+     * The pts is strictly not correct if we have samples kept from
+     * a previous buffer, but the frames are so small it should be OK.
+     */
+    p_block->i_dts = p_block->i_pts = p_aout_buf->i_pts;
+    p_block->i_length = (int64_t)i_num_frames * p_sys->i_frame_samples * CLOCK_FREQ / p_sys->i_rate;
+
+    return p_block;
+}
+
 /*****************************************************************************
  *
  *****************************************************************************/