]> git.sesse.net Git - vlc/blobdiff - modules/packetizer/flac.c
Lua: code cosmetic
[vlc] / modules / packetizer / flac.c
index 3df766df99169d3cdc371f55b13adedc845d3e6f..e8e82981820908581e22d21efb105fdc6ba82366 100644 (file)
@@ -56,6 +56,7 @@ vlc_module_end()
  * decoder_sys_t : FLAC decoder descriptor
  *****************************************************************************/
 #define MAX_FLAC_HEADER_SIZE 16
+#define MIN_FLAC_FRAME_SIZE ((48+(8 + 4 + 1*4)+16)/8)
 struct decoder_sys_t
 {
     /*
@@ -82,12 +83,15 @@ struct decoder_sys_t
     /*
      * Common properties
      */
-    date_t  end_date;
     mtime_t i_pts;
+    mtime_t i_duration;
 
     int i_frame_length;
     size_t i_frame_size;
+    uint16_t crc;
     unsigned int i_rate, i_channels, i_bits_per_sample;
+    size_t i_buf;
+    uint8_t *p_buf;
 };
 
 static const int pi_channels_maps[9] =
@@ -133,9 +137,15 @@ static void ProcessHeader(decoder_t *p_dec)
     bs_init(&bs, p_extra, i_extra);
 
     p_sys->stream_info.min_blocksize = bs_read(&bs, 16);
+    p_sys->stream_info.min_blocksize =
+            __MIN( __MAX( p_sys->stream_info.min_blocksize, 16 ), 65535 );
     p_sys->stream_info.max_blocksize = bs_read(&bs, 16);
+    p_sys->stream_info.max_blocksize =
+                __MAX( __MIN( p_sys->stream_info.max_blocksize, 65535 ), 16 );
 
     p_sys->stream_info.min_framesize = bs_read(&bs, 24);
+    p_sys->stream_info.min_framesize =
+            __MAX( p_sys->stream_info.min_framesize, MIN_FLAC_FRAME_SIZE );
     p_sys->stream_info.max_framesize = bs_read(&bs, 24);
 
     p_sys->stream_info.sample_rate = bs_read(&bs, 20);
@@ -153,10 +163,12 @@ static void ProcessHeader(decoder_t *p_dec)
         p_dec->fmt_out.i_extra = 0;
 }
 
-/* Will return 0xffffffffffffffff for an invalid utf-8 sequence */
-static uint64_t read_utf8(const uint8_t *p_buf, int *pi_read)
+/* Will return INT64_MAX for an invalid utf-8 sequence */
+static int64_t read_utf8(const uint8_t *p_buf, int *pi_read)
 {
-    uint64_t i_result = 0;
+    /* Max coding bits is 56 - 8 */
+    /* Value max precision is 36 bits */
+    int64_t i_result = 0;
     unsigned i;
 
     if (!(p_buf[0] & 0x80)) { /* 0xxxxxxx */
@@ -181,12 +193,12 @@ static uint64_t read_utf8(const uint8_t *p_buf, int *pi_read)
         i_result = 0;
         i = 6;
     } else {
-        return INT64_C(0xffffffffffffffff);
+        return INT64_MAX;
     }
 
     for (unsigned j = 1; j <= i; j++) {
         if (!(p_buf[j] & 0x80) || (p_buf[j] & 0x40)) { /* 10xxxxxx */
-            return INT64_C(0xffffffffffffffff);
+            return INT64_MAX;
         }
         i_result <<= 6;
         i_result |= (p_buf[j] & 0x3F);
@@ -242,13 +254,102 @@ static uint8_t flac_crc8(const uint8_t *data, unsigned len)
     return crc;
 }
 
+/* CRC-16, poly = x^16 + x^15 + x^2 + x^0, init = 0 */
+static const uint16_t flac_crc16_table[256] = {
+    0x0000,  0x8005,  0x800f,  0x000a,  0x801b,  0x001e,  0x0014,  0x8011,
+    0x8033,  0x0036,  0x003c,  0x8039,  0x0028,  0x802d,  0x8027,  0x0022,
+    0x8063,  0x0066,  0x006c,  0x8069,  0x0078,  0x807d,  0x8077,  0x0072,
+    0x0050,  0x8055,  0x805f,  0x005a,  0x804b,  0x004e,  0x0044,  0x8041,
+    0x80c3,  0x00c6,  0x00cc,  0x80c9,  0x00d8,  0x80dd,  0x80d7,  0x00d2,
+    0x00f0,  0x80f5,  0x80ff,  0x00fa,  0x80eb,  0x00ee,  0x00e4,  0x80e1,
+    0x00a0,  0x80a5,  0x80af,  0x00aa,  0x80bb,  0x00be,  0x00b4,  0x80b1,
+    0x8093,  0x0096,  0x009c,  0x8099,  0x0088,  0x808d,  0x8087,  0x0082,
+    0x8183,  0x0186,  0x018c,  0x8189,  0x0198,  0x819d,  0x8197,  0x0192,
+    0x01b0,  0x81b5,  0x81bf,  0x01ba,  0x81ab,  0x01ae,  0x01a4,  0x81a1,
+    0x01e0,  0x81e5,  0x81ef,  0x01ea,  0x81fb,  0x01fe,  0x01f4,  0x81f1,
+    0x81d3,  0x01d6,  0x01dc,  0x81d9,  0x01c8,  0x81cd,  0x81c7,  0x01c2,
+    0x0140,  0x8145,  0x814f,  0x014a,  0x815b,  0x015e,  0x0154,  0x8151,
+    0x8173,  0x0176,  0x017c,  0x8179,  0x0168,  0x816d,  0x8167,  0x0162,
+    0x8123,  0x0126,  0x012c,  0x8129,  0x0138,  0x813d,  0x8137,  0x0132,
+    0x0110,  0x8115,  0x811f,  0x011a,  0x810b,  0x010e,  0x0104,  0x8101,
+    0x8303,  0x0306,  0x030c,  0x8309,  0x0318,  0x831d,  0x8317,  0x0312,
+    0x0330,  0x8335,  0x833f,  0x033a,  0x832b,  0x032e,  0x0324,  0x8321,
+    0x0360,  0x8365,  0x836f,  0x036a,  0x837b,  0x037e,  0x0374,  0x8371,
+    0x8353,  0x0356,  0x035c,  0x8359,  0x0348,  0x834d,  0x8347,  0x0342,
+    0x03c0,  0x83c5,  0x83cf,  0x03ca,  0x83db,  0x03de,  0x03d4,  0x83d1,
+    0x83f3,  0x03f6,  0x03fc,  0x83f9,  0x03e8,  0x83ed,  0x83e7,  0x03e2,
+    0x83a3,  0x03a6,  0x03ac,  0x83a9,  0x03b8,  0x83bd,  0x83b7,  0x03b2,
+    0x0390,  0x8395,  0x839f,  0x039a,  0x838b,  0x038e,  0x0384,  0x8381,
+    0x0280,  0x8285,  0x828f,  0x028a,  0x829b,  0x029e,  0x0294,  0x8291,
+    0x82b3,  0x02b6,  0x02bc,  0x82b9,  0x02a8,  0x82ad,  0x82a7,  0x02a2,
+    0x82e3,  0x02e6,  0x02ec,  0x82e9,  0x02f8,  0x82fd,  0x82f7,  0x02f2,
+    0x02d0,  0x82d5,  0x82df,  0x02da,  0x82cb,  0x02ce,  0x02c4,  0x82c1,
+    0x8243,  0x0246,  0x024c,  0x8249,  0x0258,  0x825d,  0x8257,  0x0252,
+    0x0270,  0x8275,  0x827f,  0x027a,  0x826b,  0x026e,  0x0264,  0x8261,
+    0x0220,  0x8225,  0x822f,  0x022a,  0x823b,  0x023e,  0x0234,  0x8231,
+    0x8213,  0x0216,  0x021c,  0x8219,  0x0208,  0x820d,  0x8207,  0x0202
+};
+
+static uint16_t flac_crc16(uint16_t crc, uint8_t byte)
+{
+    return (crc << 8) ^ flac_crc16_table[(crc >> 8) ^ byte];
+}
+
+/* Gives the previous CRC value, before hashing last_byte through it */
+static uint16_t flac_crc16_undo(uint16_t crc, const uint8_t last_byte)
+{
+    /*
+     * Given a byte b, gives a position X in flac_crc16_table, such as:
+     *      flac_crc16_rev_table[flac_crc16_table[X] & 0xff] == X
+     * This works because flac_crc16_table[i] & 0xff yields 256 unique values.
+     */
+    static const uint8_t flac_crc16_rev_table[256] = {
+        0x00, 0x7f, 0xff, 0x80, 0x7e, 0x01, 0x81, 0xfe,
+        0xfc, 0x83, 0x03, 0x7c, 0x82, 0xfd, 0x7d, 0x02,
+        0x78, 0x07, 0x87, 0xf8, 0x06, 0x79, 0xf9, 0x86,
+        0x84, 0xfb, 0x7b, 0x04, 0xfa, 0x85, 0x05, 0x7a,
+        0xf0, 0x8f, 0x0f, 0x70, 0x8e, 0xf1, 0x71, 0x0e,
+        0x0c, 0x73, 0xf3, 0x8c, 0x72, 0x0d, 0x8d, 0xf2,
+        0x88, 0xf7, 0x77, 0x08, 0xf6, 0x89, 0x09, 0x76,
+        0x74, 0x0b, 0x8b, 0xf4, 0x0a, 0x75, 0xf5, 0x8a,
+        0x60, 0x1f, 0x9f, 0xe0, 0x1e, 0x61, 0xe1, 0x9e,
+        0x9c, 0xe3, 0x63, 0x1c, 0xe2, 0x9d, 0x1d, 0x62,
+        0x18, 0x67, 0xe7, 0x98, 0x66, 0x19, 0x99, 0xe6,
+        0xe4, 0x9b, 0x1b, 0x64, 0x9a, 0xe5, 0x65, 0x1a,
+        0x90, 0xef, 0x6f, 0x10, 0xee, 0x91, 0x11, 0x6e,
+        0x6c, 0x13, 0x93, 0xec, 0x12, 0x6d, 0xed, 0x92,
+        0xe8, 0x97, 0x17, 0x68, 0x96, 0xe9, 0x69, 0x16,
+        0x14, 0x6b, 0xeb, 0x94, 0x6a, 0x15, 0x95, 0xea,
+        0xc0, 0xbf, 0x3f, 0x40, 0xbe, 0xc1, 0x41, 0x3e,
+        0x3c, 0x43, 0xc3, 0xbc, 0x42, 0x3d, 0xbd, 0xc2,
+        0xb8, 0xc7, 0x47, 0x38, 0xc6, 0xb9, 0x39, 0x46,
+        0x44, 0x3b, 0xbb, 0xc4, 0x3a, 0x45, 0xc5, 0xba,
+        0x30, 0x4f, 0xcf, 0xb0, 0x4e, 0x31, 0xb1, 0xce,
+        0xcc, 0xb3, 0x33, 0x4c, 0xb2, 0xcd, 0x4d, 0x32,
+        0x48, 0x37, 0xb7, 0xc8, 0x36, 0x49, 0xc9, 0xb6,
+        0xb4, 0xcb, 0x4b, 0x34, 0xca, 0xb5, 0x35, 0x4a,
+        0xa0, 0xdf, 0x5f, 0x20, 0xde, 0xa1, 0x21, 0x5e,
+        0x5c, 0x23, 0xa3, 0xdc, 0x22, 0x5d, 0xdd, 0xa2,
+        0xd8, 0xa7, 0x27, 0x58, 0xa6, 0xd9, 0x59, 0x26,
+        0x24, 0x5b, 0xdb, 0xa4, 0x5a, 0x25, 0xa5, 0xda,
+        0x50, 0x2f, 0xaf, 0xd0, 0x2e, 0x51, 0xd1, 0xae,
+        0xac, 0xd3, 0x53, 0x2c, 0xd2, 0xad, 0x2d, 0x52,
+        0x28, 0x57, 0xd7, 0xa8, 0x56, 0x29, 0xa9, 0xd6,
+        0xd4, 0xab, 0x2b, 0x54, 0xaa, 0xd5, 0x55, 0x2a,
+    };
+    uint8_t idx = flac_crc16_rev_table[crc & 0xff];
+    return ((idx ^ last_byte) << 8) | ((crc ^ flac_crc16_table[idx]) >> 8);
+}
+
 /*****************************************************************************
  * SyncInfo: parse FLAC sync info
  *****************************************************************************/
 static int SyncInfo(decoder_t *p_dec, uint8_t *p_buf,
                      unsigned int * pi_channels,
                      unsigned int * pi_sample_rate,
-                     unsigned int * pi_bits_per_sample)
+                     unsigned int * pi_bits_per_sample,
+                     mtime_t * pi_pts,
+                     mtime_t * pi_duration )
 {
     decoder_sys_t *p_sys = p_dec->p_sys;
 
@@ -280,7 +381,7 @@ static int SyncInfo(decoder_t *p_dec, uint8_t *p_buf,
         blocksize = 576 << (blocksize - 2);
     }
 
-    if (p_sys->b_stream_info)
+    if (p_sys->b_stream_info && !blocksize_hint )
         if (blocksize < p_sys->stream_info.min_blocksize ||
             blocksize > p_sys->stream_info.max_blocksize)
             return 0;
@@ -339,7 +440,8 @@ static int SyncInfo(decoder_t *p_dec, uint8_t *p_buf,
 
     /* Check Sample/Frame number */
     int i_read;
-    if (read_utf8(&p_buf[i_header++], &i_read) == INT64_C(0xffffffffffffffff))
+    int64_t i_fsnumber = read_utf8(&p_buf[i_header++], &i_read);
+    if ( i_fsnumber == INT64_MAX )
         return 0;
 
     i_header += i_read;
@@ -368,6 +470,9 @@ static int SyncInfo(decoder_t *p_dec, uint8_t *p_buf,
             samplerate *= 10;
     }
 
+    if ( !samplerate )
+        return 0;
+
     /* Check the CRC-8 byte */
     if (flac_crc8(p_buf, i_header) != p_buf[i_header])
         return 0;
@@ -383,6 +488,18 @@ static int SyncInfo(decoder_t *p_dec, uint8_t *p_buf,
             return 0;
     }
 
+    if( pi_pts )
+    {
+        *pi_pts = VLC_TS_0;
+        if ( (p_buf[1] & 0x01) == 0  ) /* Fixed blocksize stream / Frames */
+            *pi_pts += CLOCK_FREQ * blocksize * i_fsnumber / samplerate;
+        else /* Variable blocksize stream / Samples */
+            *pi_pts += CLOCK_FREQ * i_fsnumber / samplerate;
+    }
+
+    if ( pi_duration )
+        *pi_duration = CLOCK_FREQ * blocksize / samplerate;
+
     *pi_bits_per_sample = bits_per_sample;
     *pi_sample_rate = samplerate;
     *pi_channels = channels;
@@ -395,162 +512,230 @@ static block_t *Packetize(decoder_t *p_dec, block_t **pp_block)
 {
     decoder_sys_t *p_sys = p_dec->p_sys;
     uint8_t p_header[MAX_FLAC_HEADER_SIZE];
-    block_t *out;
-
-    if (!pp_block || !*pp_block)
-        return NULL;
+    block_t *out, *in = NULL;
 
-    block_t *in = *pp_block;
+    if ( pp_block && *pp_block)
+    {
+        in = *pp_block;
 
-    if (in->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED)) {
-        if (in->i_flags&BLOCK_FLAG_CORRUPTED) {
-            p_sys->i_state = STATE_NOSYNC;
-            block_BytestreamEmpty(&p_sys->bytestream);
+        if (in->i_flags&(BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED)) {
+            if (in->i_flags&BLOCK_FLAG_CORRUPTED) {
+                p_sys->i_state = STATE_NOSYNC;
+                block_BytestreamEmpty(&p_sys->bytestream);
+            }
+            block_Release(*pp_block);
+            return NULL;
         }
-        date_Set(&p_sys->end_date, 0);
-        block_Release(*pp_block);
-        return NULL;
     }
 
     if (!p_sys->b_stream_info)
         ProcessHeader(p_dec);
 
     if (p_sys->stream_info.channels > 8) {
-        msg_Err(p_dec, "This stream uses too many audio channels");
+        msg_Err(p_dec, "This stream uses too many audio channels (%d > 8)",
+            p_sys->stream_info.channels);
         return NULL;
     }
 
-    if (!date_Get(&p_sys->end_date) && in->i_pts <= VLC_TS_INVALID) {
-        /* We've just started the stream, wait for the first PTS. */
-        block_Release(in);
-        return NULL;
-    } else if (!date_Get(&p_sys->end_date)) {
-        /* The first PTS is as good as anything else. */
+    if ( p_sys->i_pts <= VLC_TS_INVALID )
+    {
+        if ( in && in->i_pts == p_sys->i_pts )
+        {
+            /* We've just started the stream, wait for the first PTS. */
+            block_Release(in);
+            return NULL;
+        }
         p_sys->i_rate = p_dec->fmt_out.audio.i_rate;
-        date_Init(&p_sys->end_date, p_sys->i_rate, 1);
-        date_Set(&p_sys->end_date, in->i_pts);
     }
 
-    block_BytestreamPush(&p_sys->bytestream, in);
+    if ( in )
+        block_BytestreamPush(&p_sys->bytestream, in);
 
-    while (1) {
-        switch (p_sys->i_state) {
-        case STATE_NOSYNC:
-            while (block_PeekBytes(&p_sys->bytestream, p_header, 2)
-                   == VLC_SUCCESS) {
-                if (p_header[0] == 0xFF && (p_header[1] & 0xFE) == 0xF8) {
-                    p_sys->i_state = STATE_SYNC;
-                    break;
-                }
-                block_SkipByte(&p_sys->bytestream);
+    while (1) switch (p_sys->i_state) {
+    case STATE_NOSYNC:
+        while (!block_PeekBytes(&p_sys->bytestream, p_header, 2)) {
+            if (p_header[0] == 0xFF && (p_header[1] & 0xFE) == 0xF8) {
+                p_sys->i_state = STATE_SYNC;
+                break;
             }
-            if (p_sys->i_state != STATE_SYNC) {
-                block_BytestreamFlush(&p_sys->bytestream);
-                return NULL; /* Need more data */
+            block_SkipByte(&p_sys->bytestream);
+        }
+        if (p_sys->i_state != STATE_SYNC) {
+            block_BytestreamFlush(&p_sys->bytestream);
+            return NULL; /* Need more data */
+        }
+
+    case STATE_SYNC:
+        /* Sync state is unverified until we have read frame header and checked CRC
+           Once validated, we'll send data from NEXT_SYNC state where we'll
+           compute frame size */
+        p_sys->i_state = STATE_HEADER;
+
+    case STATE_HEADER:
+        /* Get FLAC frame header (MAX_FLAC_HEADER_SIZE bytes) */
+        if (block_PeekBytes(&p_sys->bytestream, p_header, MAX_FLAC_HEADER_SIZE))
+            return NULL; /* Need more data */
+
+        /* Check if frame is valid and get frame info */
+        p_sys->i_frame_length = SyncInfo(p_dec, p_header,
+                                          &p_sys->i_channels,
+                                          &p_sys->i_rate,
+                                          &p_sys->i_bits_per_sample,
+                                          &p_sys->i_pts,
+                                          &p_sys->i_duration );
+        if (!p_sys->i_frame_length) {
+            msg_Dbg(p_dec, "emulated sync word");
+            block_SkipByte(&p_sys->bytestream);
+            p_sys->i_state = STATE_NOSYNC;
+            break;
+        }
+        if (p_sys->i_rate != p_dec->fmt_out.audio.i_rate) {
+            p_dec->fmt_out.audio.i_rate = p_sys->i_rate;
+        }
+        p_sys->i_state = STATE_NEXT_SYNC;
+        p_sys->i_frame_size = ( p_sys->b_stream_info ) ? p_sys->stream_info.min_framesize :
+                                                         MIN_FLAC_FRAME_SIZE;
+
+        /* We have to read until next frame sync code to compute current frame size
+         * from that boundary.
+         * The confusing part below is that sync code needs to be verified in case
+         * it would appear in data, so we also need to check next frame header CRC
+         */
+    case STATE_NEXT_SYNC:
+    {
+        /* Calculate the initial CRC for the minimal frame size,
+         * We'll update it as we look for the next start code. */
+        if (p_sys->i_buf < p_sys->i_frame_size)
+        {
+            uint8_t *p_buf = realloc(p_sys->p_buf, p_sys->i_frame_size);
+            if (!p_buf)
+                return NULL;
+            p_sys->p_buf = p_buf;
+            p_sys->i_buf = p_sys->i_frame_size;
+        }
+
+        if (block_PeekOffsetBytes(&p_sys->bytestream, 0, p_sys->p_buf, p_sys->i_frame_size)) {
+            return NULL;
+        }
+
+        uint16_t crc = 0;
+        for (unsigned i = 0; i < p_sys->i_frame_size; i++)
+            crc = flac_crc16(crc, p_sys->p_buf[i]);
+        p_sys->crc = crc;
+
+        /* Check if next expected frame contains the sync word */
+        while (!block_PeekOffsetBytes(&p_sys->bytestream, p_sys->i_frame_size,
+                    p_header, MAX_FLAC_HEADER_SIZE)) {
+            if (p_header[0] == 0xFF && (p_header[1] & 0xFE) == 0xF8) {
+                /* Check if frame is valid and get frame info */
+                int i_frame_length =
+                    SyncInfo(p_dec, p_header,
+                              &p_sys->i_channels,
+                              &p_sys->i_rate,
+                              &p_sys->i_bits_per_sample,
+                              NULL, NULL );
+
+                if (i_frame_length) {
+                    uint8_t crc_bytes[2];
+                    block_PeekOffsetBytes(&p_sys->bytestream,
+                        p_sys->i_frame_size - 2, crc_bytes, 2);
+                    /* Get the frame CRC */
+                    uint16_t stream_crc = (crc_bytes[0] << 8) | crc_bytes[1];
+                    /* Calculate the frame CRC: remove the last 2 bytes */
+                    uint16_t crc = flac_crc16_undo(p_sys->crc, crc_bytes[1]);
+                             crc = flac_crc16_undo(crc,        crc_bytes[0]);
+                    if (stream_crc != crc) {
+                        msg_Warn(p_dec, "Bad CRC for frame size %zu: 0x%x != 0x%x",
+                            p_sys->i_frame_size, crc, stream_crc);
+                        block_SkipByte(&p_sys->bytestream);
+                        p_sys->i_state = STATE_NOSYNC;
+                    } else {
+                        p_sys->i_state = STATE_SEND_DATA;
+                        p_sys->crc = 0;
+                        break;
+                    }
+                }
             }
+            p_sys->crc = flac_crc16(p_sys->crc, p_header[0]); /* update CRC */
+            p_sys->i_frame_size++;
+        }
 
-        case STATE_SYNC:
-            /* New frame, set the Presentation Time Stamp */
-            p_sys->i_pts = p_sys->bytestream.p_block->i_pts;
-            if (p_sys->i_pts > VLC_TS_INVALID &&
-                p_sys->i_pts != date_Get(&p_sys->end_date))
-                date_Set(&p_sys->end_date, p_sys->i_pts);
-            p_sys->i_state = STATE_HEADER;
-
-        case STATE_HEADER:
-            /* Get FLAC frame header (MAX_FLAC_HEADER_SIZE bytes) */
-            if (block_PeekBytes(&p_sys->bytestream, p_header,
-                                 MAX_FLAC_HEADER_SIZE) != VLC_SUCCESS)
-                return NULL; /* Need more data */
-
-            /* Check if frame is valid and get frame info */
-            p_sys->i_frame_length = SyncInfo(p_dec, p_header,
-                                              &p_sys->i_channels,
-                                              &p_sys->i_rate,
-                                              &p_sys->i_bits_per_sample);
-            if (!p_sys->i_frame_length) {
-                msg_Dbg(p_dec, "emulated sync word");
+        if (p_sys->i_state != STATE_SEND_DATA) {
+            if (p_sys->b_stream_info && p_sys->stream_info.max_framesize > 0 &&
+                p_sys->i_frame_size > p_sys->stream_info.max_framesize) {
                 block_SkipByte(&p_sys->bytestream);
+                msg_Warn(p_dec, "Frame is too big (%zu > %d), couldn't find start code",
+                        p_sys->i_frame_size, p_sys->stream_info.max_framesize);
                 p_sys->i_state = STATE_NOSYNC;
-                break;
-            }
-            if (p_sys->i_rate != p_dec->fmt_out.audio.i_rate) {
-                p_dec->fmt_out.audio.i_rate = p_sys->i_rate;
-                const mtime_t i_end_date = date_Get(&p_sys->end_date);
-                date_Init(&p_sys->end_date, p_sys->i_rate, 1);
-                date_Set(&p_sys->end_date, i_end_date);
+                return NULL;
             }
-            p_sys->i_state = STATE_NEXT_SYNC;
-            p_sys->i_frame_size = p_sys->b_stream_info && p_sys->stream_info.min_framesize > 0 ?
-                                                            p_sys->stream_info.min_framesize : 1;
-
-        case STATE_NEXT_SYNC:
-            /* TODO: If pp_block == NULL, flush the buffer without checking the
-             * next sync word */
-
-            /* Check if next expected frame contains the sync word */
-            while (block_PeekOffsetBytes(&p_sys->bytestream,
-                                          p_sys->i_frame_size, p_header,
-                                          MAX_FLAC_HEADER_SIZE)
-                   == VLC_SUCCESS) {
-                if (p_header[0] == 0xFF && (p_header[1] & 0xFE) == 0xF8) {
-                    /* Check if frame is valid and get frame info */
-                    int i_frame_length =
-                        SyncInfo(p_dec, p_header,
-                                  &p_sys->i_channels,
-                                  &p_sys->i_rate,
-                                  &p_sys->i_bits_per_sample);
-
-                    if (i_frame_length) {
-                        p_sys->i_state = STATE_SEND_DATA;
-                        break;
+
+            if ( !in )
+            {
+                /* There's no following frame, so we need to read current
+                 * data until the frame footer matches (crc16) == stream crc.
+                 * In the worst case, if crc might be a false positive and data
+                 * will be truncated. */
+                uint8_t crc_bytes[2];
+                if ( !block_PeekOffsetBytes(&p_sys->bytestream,
+                                    p_sys->i_frame_size - 2, crc_bytes, 2) )
+                {
+                    while ( true )
+                    {
+                        /* Read the frame CRC */
+                        uint16_t stream_crc = (crc_bytes[0] << 8) | crc_bytes[1];
+                        /* Calculate the frame CRC: remove the last 2 bytes */
+                        uint16_t crc = flac_crc16_undo(p_sys->crc, crc_bytes[1]);
+                                 crc = flac_crc16_undo(crc,        crc_bytes[0]);
+                        if (stream_crc == crc)
+                        {
+                            p_sys->i_state = STATE_SEND_DATA;
+                            break;
+                        }
+                        p_sys->i_frame_size++;
+                        if ( block_PeekOffsetBytes(&p_sys->bytestream,
+                                                   p_sys->i_frame_size - 2, crc_bytes, 2) )
+                            break;
+                        /* Update current crc */
+                        p_sys->crc = flac_crc16(p_sys->crc, crc_bytes[1]);
                     }
                 }
-                p_sys->i_frame_size++;
-            }
 
-            if (p_sys->i_state != STATE_SEND_DATA) {
-                if (p_sys->b_stream_info && p_sys->stream_info.max_framesize > 0 &&
-                    p_sys->i_frame_size > p_sys->stream_info.max_framesize) {
-                    block_SkipByte(&p_sys->bytestream);
-                    p_sys->i_state = STATE_NOSYNC;
+                if ( p_sys->i_state != STATE_SEND_DATA )
                     return NULL;
-                }
+            }
+            else
+            {
                 /* Need more data */
                 return NULL;
             }
+        }
+    }
+    case STATE_SEND_DATA:
+        out = block_Alloc(p_sys->i_frame_size);
 
-        case STATE_SEND_DATA:
-            out = block_Alloc(p_sys->i_frame_size);
-
-            /* Copy the whole frame into the buffer. When we reach this point
-             * we already know we have enough data available. */
-            block_GetBytes(&p_sys->bytestream, out->p_buffer,
-                            p_sys->i_frame_size);
-
-            /* Make sure we don't reuse the same pts twice */
-            if (p_sys->i_pts == p_sys->bytestream.p_block->i_pts)
-                p_sys->i_pts = p_sys->bytestream.p_block->i_pts = VLC_TS_INVALID;
+        /* Copy the whole frame into the buffer. When we reach this point
+         * we already know we have enough data available. */
+        block_GetBytes(&p_sys->bytestream, out->p_buffer,
+                        p_sys->i_frame_size);
 
-            p_dec->fmt_out.audio.i_channels = p_sys->i_channels;
-            p_dec->fmt_out.audio.i_physical_channels =
-                p_dec->fmt_out.audio.i_original_channels =
-                    pi_channels_maps[p_sys->stream_info.channels];
+        p_dec->fmt_out.audio.i_channels = p_sys->i_channels;
+        p_dec->fmt_out.audio.i_physical_channels =
+            p_dec->fmt_out.audio.i_original_channels =
+                pi_channels_maps[p_sys->stream_info.channels];
 
-            /* So p_block doesn't get re-added several times */
+        /* So p_block doesn't get re-added several times */
+        if ( in )
             *pp_block = block_BytestreamPop(&p_sys->bytestream);
+        else
+            block_BytestreamFlush(&p_sys->bytestream);
 
-            p_sys->i_state = STATE_NOSYNC;
+        p_sys->i_state = STATE_NOSYNC;
 
-            /* Date management */
-            out->i_pts =
-                out->i_dts = date_Get(&p_sys->end_date);
-            date_Increment(&p_sys->end_date, p_sys->i_frame_length);
-            out->i_length =
-                date_Get(&p_sys->end_date) - out->i_pts;
+        out->i_dts = out->i_pts = p_sys->i_pts;
+        out->i_length = p_sys->i_duration;
 
-            return out;
-        }
+        return out;
     }
 
     return NULL;
@@ -569,10 +754,11 @@ static int Open(vlc_object_t *p_this)
     if (!p_sys)
         return VLC_ENOMEM;
 
-    date_Set(&p_sys->end_date, 0);
     p_sys->i_state       = STATE_NOSYNC;
     p_sys->b_stream_info = false;
     p_sys->i_pts         = VLC_TS_INVALID;
+    p_sys->i_buf         = 0;
+    p_sys->p_buf         = NULL;
     block_BytestreamInit(&p_sys->bytestream);
 
     /* */
@@ -592,6 +778,8 @@ static void Close(vlc_object_t *p_this)
     decoder_t *p_dec = (decoder_t *)p_this;
     decoder_sys_t *p_sys = p_dec->p_sys;
 
+    es_format_Clean(&p_dec->fmt_out);
     block_BytestreamRelease(&p_sys->bytestream);
+    free(p_sys->p_buf);
     free(p_sys);
 }