mpegplayer: Make playback engine fully seekable and frame-accurate and split into logical parts. Be sure to have all current features work. Actual UI for seeking will be added soon. Recommended GOP size is about 15-30 frames depending on target or seeking can be slow with really long GOPs (nature of MPEG video). More refined encoding recommendations for a particular player should be posted soon.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@15977 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 1182 insertions, 0 deletions

diff --git a/apps/plugins/mpegplayer/mpeg_parser.c b/apps/plugins/mpegplayer/mpeg_parser.c
new file mode 100644
index 0000000..c996f95
--- /dev/null
+++ b/apps/plugins/mpegplayer/mpeg_parser.c
@@ -0,0 +1,1182 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Parser for MPEG streams
+ *
+ * Copyright (c) 2007 Michael Sevakis
+ *
+ * All files in this archive are subject to the GNU General Public License.
+ * See the file COPYING in the source tree root for full license agreement.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#include "plugin.h"
+#include "mpegplayer.h"
+
+struct stream_parser str_parser NOCACHEBSS_ATTR;
+
+static void parser_init_state(void)
+{
+    str_parser.last_seek_time = 0;
+    str_parser.format = STREAM_FMT_UNKNOWN;
+    str_parser.start_pts = INVALID_TIMESTAMP;
+    str_parser.end_pts = INVALID_TIMESTAMP;
+    str_parser.flags = 0;
+    str_parser.dims.w = 0;
+    str_parser.dims.h = 0;
+}
+
+/* Place the stream in a state to begin parsing - sync will be performed
+ * first */
+void str_initialize(struct stream *str, off_t pos)
+{
+    /* Initial positions start here */
+    str->hdr.win_left = str->hdr.win_right = pos;
+    /* No packet */
+    str->curr_packet = NULL;
+    /* Pick up parsing from this point in the buffer */
+    str->curr_packet_end = disk_buf_offset2ptr(pos);
+    /* No flags */
+    str->pkt_flags = 0;
+    /* Sync first */
+    str->state = SSTATE_SYNC;
+}
+
+/* Place the stream in an end of data state */
+void str_end_of_stream(struct stream *str)
+{
+    /* Offsets that prevent this stream from being included in the
+     * min left/max right window so that no buffering is triggered on
+     * its behalf. Set right to the min first so a thread reading the
+     * overall window gets doesn't see this as valid no matter what the
+     * file length. */
+    str->hdr.win_right = LONG_MIN;
+    str->hdr.win_left = LONG_MAX;
+    /* No packets */
+    str->curr_packet = str->curr_packet_end = NULL;
+    /* No flags */
+    str->pkt_flags = 0;
+    /* Fin */
+    str->state = SSTATE_END;
+}
+
+/* Return a timestamp at address p+offset if the marker bits are in tact */
+static inline uint32_t read_pts(uint8_t *p, off_t offset)
+{
+    return TS_CHECK_MARKERS(p, offset) ?
+        TS_FROM_HEADER(p, offset) : INVALID_TIMESTAMP;
+}
+
+static inline bool validate_timestamp(uint32_t ts)
+{
+    return ts >= str_parser.start_pts && ts <= str_parser.end_pts;
+}
+
+/* Find a start code before or after a given position */
+uint8_t * mpeg_parser_scan_start_code(struct stream_scan *sk, uint32_t code)
+{
+    stream_scan_normalize(sk);
+
+    if (sk->dir < 0)
+    {
+        /* Reverse scan - start with at least the min needed */
+        stream_scan_offset(sk, 4);
+    }
+
+    code &= 0xff; /* Only the low byte matters */
+
+    while (sk->len >= 0 && sk->margin >= 4)
+    {
+        uint8_t *p;
+        off_t pos = disk_buf_lseek(sk->pos, SEEK_SET);
+        ssize_t len = disk_buf_getbuffer(4, &p, NULL, NULL);
+
+        if (pos < 0 || len < 4)
+            break;
+
+        if (CMP_3_CONST(p, PACKET_START_CODE_PREFIX) && p[3] == code)
+        {
+            return p;
+        }
+
+        stream_scan_offset(sk, 1);
+    }
+
+    return NULL;
+}
+
+/* Find a PES packet header for any stream - return stream to which it
+ * belongs */
+unsigned mpeg_parser_scan_pes(struct stream_scan *sk)
+{
+    stream_scan_normalize(sk);
+
+    if (sk->dir < 0)
+    {
+        /* Reverse scan - start with at least the min needed */
+        stream_scan_offset(sk, 4);
+    }
+
+    while (sk->len >= 0 && sk->margin >= 4)
+    {
+        uint8_t *p;
+        off_t pos = disk_buf_lseek(sk->pos, SEEK_SET);
+        ssize_t len = disk_buf_getbuffer(4, &p, NULL, NULL);
+
+        if (pos < 0 || len < 4)
+            break;
+
+        if (CMP_3_CONST(p, PACKET_START_CODE_PREFIX))
+        {
+            unsigned id = p[3];
+            if (id >= 0xb9)
+                return id;  /* PES header */
+            /* else some video stream element */
+        }
+
+        stream_scan_offset(sk, 1);
+    }
+
+    return -1;
+}
+
+/* Return the first SCR found from the scan direction */
+uint32_t mpeg_parser_scan_scr(struct stream_scan *sk)
+{
+    uint8_t *p = mpeg_parser_scan_start_code(sk, MPEG_STREAM_PACK_HEADER);
+
+    if (p != NULL && sk->margin >= 9) /* 9 bytes total required */
+    {
+        sk->data = 9;
+
+        if ((p[4] & 0xc0) == 0x40)      /* mpeg-2 */
+        {
+            /* Lookhead p+8 */
+            if (MPEG2_CHECK_PACK_SCR_MARKERS(p, 4))
+                return MPEG2_PACK_HEADER_SCR(p, 4);
+        }
+        else if ((p[4] & 0xf0) == 0x20) /* mpeg-1 */
+        {
+            /* Lookahead p+8 */
+            if (TS_CHECK_MARKERS(p, 4))
+                return TS_FROM_HEADER(p, 4);
+        }
+        /* Weird pack header */
+        sk->data = 5;
+    }
+
+    return INVALID_TIMESTAMP;
+}
+
+uint32_t mpeg_parser_scan_pts(struct stream_scan *sk, unsigned id)
+{
+    stream_scan_normalize(sk);
+
+    if (sk->dir < 0)
+    {
+        /* Reverse scan - start with at least the min needed */
+        stream_scan_offset(sk, 4);
+    }
+
+    while (sk->len >= 0 && sk->margin >= 4)
+    {
+        uint8_t *p;
+        off_t pos = disk_buf_lseek(sk->pos, SEEK_SET);
+        ssize_t len = disk_buf_getbuffer(35, &p, NULL, NULL);
+
+        if (pos < 0 || len < 4)
+            break;
+
+        if (CMP_3_CONST(p, PACKET_START_CODE_PREFIX) && p[3] == id)
+        {
+            uint8_t *h = p;
+
+            if (sk->margin < 6)
+            {
+                /* Insufficient data */
+            }
+            else if ((h[6] & 0xc0) == 0x80) /* mpeg2 */
+            {
+                if (sk->margin >= 14 && (h[7] & 0x80) != 0x00)
+                {
+                    sk->data = 14;
+                    return read_pts(h, 9);
+                }
+            }
+            else                            /* mpeg1 */
+            {
+                ssize_t l = 7;
+                ssize_t margin = sk->margin;
+
+                /* Skip stuffing_byte */
+                while (h[l - 1] == 0xff && ++l <= 23)
+                    --margin;
+
+                if ((h[l - 1] & 0xc0) == 0x40)
+                {
+                    /* Skip STD_buffer_scale and STD_buffer_size */
+                    margin -= 2;
+                    l += 2;
+                }
+
+                if (margin >= 4)
+                {
+                    /* header points to the mpeg1 pes header */
+                    h += l;
+
+                    if ((h[-1] & 0xe0) == 0x20)
+                    {
+                        sk->data = (h + 4) - p;
+                        return read_pts(h, -1);
+                    }
+                }
+            }
+            /* No PTS present - keep searching for a matching PES header with
+             * one */
+        }
+
+        stream_scan_offset(sk, 1);
+    }
+
+    return INVALID_TIMESTAMP;
+}
+
+static bool init_video_info(void)
+{
+    DEBUGF("Getting movie size\n");
+
+    /* The decoder handles this in order to initialize its knowledge of the
+     * movie parameters making seeking easier */
+    str_send_msg(&video_str, STREAM_RESET, 0);
+    if (str_send_msg(&video_str, VIDEO_GET_SIZE,
+                     (intptr_t)&str_parser.dims) != 0)
+    {
+        return true;
+    }
+
+    DEBUGF("  failed\n");
+    return false;
+}
+
+static void init_times(struct stream *str)
+{
+    int i;
+    struct stream tmp_str;
+    const ssize_t filesize = disk_buf_filesize();
+    const ssize_t max_probe = MIN(512*1024, filesize);
+
+    /* Simply find the first earliest timestamp - this will be the one
+     * used when streaming anyway */
+    DEBUGF("Finding start_pts: 0x%02x\n", str->id);
+
+    tmp_str.id = str->id;
+    tmp_str.hdr.pos = 0;
+    tmp_str.hdr.limit = max_probe;
+
+    str->start_pts = INVALID_TIMESTAMP;
+
+    /* Probe many for video because of B-frames */
+    for (i = STREAM_IS_VIDEO(str->id) ? 5 : 1; i > 0;)
+    {
+        switch (parser_get_next_data(&tmp_str, STREAM_PM_RANDOM_ACCESS))
+        {
+        case STREAM_DATA_END:
+            break;
+        case STREAM_OK:
+            if (tmp_str.pkt_flags & PKT_HAS_TS)
+            {
+                if (tmp_str.pts < str->start_pts)
+                   str->start_pts = tmp_str.pts;
+                i--; /* Decrement timestamp counter */
+            }
+            continue;
+        }
+
+        break;
+    }
+
+    DEBUGF("  start:%u\n", (unsigned)str->start_pts);
+
+    /* Use the decoder thread to perform a synchronized search - no
+     * decoding should take place but just a simple run through timestamps
+     * and durations as the decoder would see them. This should give the
+     * precise time at the end of the last frame for the stream. */
+    DEBUGF("Finding end_pts: 0x%02x\n", str->id);
+
+    str->end_pts = INVALID_TIMESTAMP;
+
+    if (str->start_pts != INVALID_TIMESTAMP)
+    {
+        str_parser.parms.sd.time = MAX_TIMESTAMP;
+        str_parser.parms.sd.sk.pos = filesize - max_probe;
+        str_parser.parms.sd.sk.len = max_probe;
+        str_parser.parms.sd.sk.dir = SSCAN_FORWARD;
+
+        str_send_msg(str, STREAM_RESET, 0);
+
+        if (str_send_msg(str, STREAM_FIND_END_TIME,
+                (intptr_t)&str_parser.parms.sd) == STREAM_PERFECT_MATCH)
+        {
+            str->end_pts = str_parser.parms.sd.time;
+            DEBUGF("  end:%u\n", (unsigned)str->end_pts);
+        }
+    }
+
+    /* End must be greater than start */
+    if (str->start_pts >= str->end_pts)
+    {
+        str->start_pts = INVALID_TIMESTAMP;
+        str->end_pts = INVALID_TIMESTAMP;
+    }
+}
+
+/* Return the best-fit file offset of a timestamp in the PES where
+ * timstamp <= time < next timestamp. Will try to return something reasonably
+ * valid if best-fit could not be made. */
+static off_t mpeg_parser_seek_PTS(uint32_t time, unsigned id)
+{
+    ssize_t pos_left = 0;
+    ssize_t pos_right = disk_buf.filesize;
+    ssize_t pos, pos_new;
+    uint32_t time_left = str_parser.start_pts;
+    uint32_t time_right = str_parser.end_pts;
+    uint32_t pts = 0;
+    uint32_t prevpts = 0;
+    enum state_enum state = state0;
+    struct stream_scan sk;
+
+    /* Initial estimate taken from average bitrate - later interpolations are
+     * taken similarly based on the remaining file interval */
+    pos_new = muldiv_uint32(time - time_left, pos_right - pos_left,
+                            time_right - time_left) + pos_left;
+
+    /* return this estimated position if nothing better comes up */
+    pos = pos_new;
+
+    DEBUGF("Seeking stream 0x%02x\n", id);
+    DEBUGF("$$ tl:%u t:%u ct:?? tr:%u\n   pl:%ld pn:%ld pr:%ld\n",
+           (unsigned)time_left, (unsigned)time, (unsigned)time_right,
+           pos_left, pos_new, pos_right);
+
+    sk.dir = SSCAN_REVERSE;
+
+    while (state < state9)
+    {
+        uint32_t currpts;
+        sk.pos = pos_new;
+        sk.len = (sk.dir < 0) ? pos_new - pos_left : pos_right - pos_new;
+
+        currpts = mpeg_parser_scan_pts(&sk, id);
+
+        if (currpts != INVALID_TIMESTAMP)
+        {
+            /* Found a valid timestamp - see were it lies in relation to
+             * target */
+            if (currpts < time)
+            {
+                /* Time at current position is before seek time - move
+                 * forward */
+                if (currpts > pts)
+                {
+                    /* This is less than the desired time but greater than
+                     * the currently seeked one; move the position up */
+                    pts = currpts;
+                    pos = sk.pos;
+                }
+
+                /* No next timestamp can be sooner */
+                pos_left = sk.pos + sk.data;
+                time_left = currpts;
+
+                if (pos_right <= pos_left)
+                    break; /* If the window disappeared - we're done */
+
+                pos_new = muldiv_uint32(time - time_left,
+                                        pos_right - pos_left,
+                                        time_right - time_left) + pos_left;
+                /* Point is ahead of us - fudge estimate a bit high */
+                pos_new = muldiv_uint32(11, pos_new - pos_left, 10)
+                                + pos_left;
+
+                if (pos_new >= pos_right)
+                {
+                    /* Estimate could push too far */
+                    pos_new = pos_right;
+                }
+
+                state = state2; /* Last scan was early */
+                sk.dir = SSCAN_REVERSE;
+   
+                DEBUGF(">> tl:%u t:%u ct:%u tr:%u\n   pl:%ld pn:%ld pr:%ld\n",
+                       (unsigned)time_left, (unsigned)time, (unsigned)currpts,
+                       (unsigned)time_right, pos_left, pos_new, pos_right);
+            }
+            else if (currpts > time)
+            {
+                /* Time at current position is past seek time - move
+                   backward */
+                pos_right = sk.pos;
+                time_right = currpts;
+
+                if (pos_right <= pos_left)
+                    break; /* If the window disappeared - we're done */
+
+                pos_new = muldiv_uint32(time - time_left,
+                                        pos_right - pos_left,
+                                        time_right - time_left) + pos_left;
+                /* Overshot the seek point - fudge estimate a bit low */
+                pos_new = muldiv_uint32(9, pos_new - pos_left, 10) + pos_left;
+
+                state = state3; /* Last scan was late */
+                sk.dir = SSCAN_REVERSE;
+
+                DEBUGF("<< tl:%u t:%u ct:%u tr:%u\n   pl:%ld pn:%ld pr:%ld\n",
+                       (unsigned)time_left, (unsigned)time, (unsigned)currpts,
+                       (unsigned)time_right, pos_left, pos_new, pos_right);
+            }
+            else
+            {
+                /* Exact match - it happens */
+                DEBUGF("|| tl:%u t:%u ct:%u tr:%u\n   pl:%ld pn:%ld pr:%ld\n",
+                       (unsigned)time_left, (unsigned)time, (unsigned)currpts,
+                       (unsigned)time_right, pos_left, pos_new, pos_right);
+                pts = currpts;
+                pos = sk.pos;
+                state = state9;
+            }
+        }
+        else
+        {
+            /* Nothing found */
+
+            switch (state)
+            {
+            case state1:
+                /* We already tried the bruteforce scan and failed again - no
+                 * more stamps could possibly exist in the interval */
+                DEBUGF("!! no timestamp 2x\n");
+                break;
+            case state0:
+                /* Hardly likely except at very beginning - just do L->R scan
+                 * to find something */
+                DEBUGF("!! no timestamp on first probe: %ld\n", sk.pos);
+            case state2:
+            case state3:
+                /* Could just be missing timestamps because the interval is
+                 * narrowing down. A large block of data from another stream
+                 * may also be in the midst of our chosen points which could
+                 * cluster at either extreme end. If anything is there, this
+                 * will find it. */
+                pos_new = pos_left;
+                sk.dir = SSCAN_FORWARD;
+                DEBUGF("?? tl:%u t:%u ct:%u tr:%u\n   pl:%ld pn:%ld pr:%ld\n",
+                       (unsigned)time_left, (unsigned)time, (unsigned)currpts,
+                       (unsigned)time_right, pos_left, pos_new, pos_right);
+                state = state1;
+                break;
+            default:
+                DEBUGF("?? Invalid state: %d\n", state);
+            }
+        }
+
+        /* Same timestamp twice = quit */
+        if (currpts == prevpts)
+        {
+            DEBUGF("!! currpts == prevpts (stop)\n");
+            state = state9;
+        }
+
+        prevpts = currpts;
+    }
+
+#if defined(DEBUG) || defined(SIMULATOR)
+    /* The next pts after the seeked-to position should be greater -
+     * most of the time - frames out of presentation order may muck it
+     * up a slight bit */
+    sk.pos = pos + 1;
+    sk.len = disk_buf.filesize;
+    sk.dir = SSCAN_FORWARD;
+
+    uint32_t nextpts = mpeg_parser_scan_pts(&sk, id);
+    DEBUGF("Seek pos:%ld pts:%u t:%u next pts:%u \n",
+        pos, (unsigned)pts, (unsigned)time, (unsigned)nextpts);
+
+    if (pts <= time && time < nextpts)
+    {
+        /* Smile - it worked */
+        DEBUGF("  :) pts<=time<next pts\n");
+    }
+    else
+    {
+        /* See where things ended up */
+        if (pts > time)
+        {
+            /* Hmm */
+            DEBUGF("  :\\ pts>time\n");
+        }
+        if (pts >= nextpts)
+        {
+            /* Weird - probably because of encoded order & tends to be right
+             * anyway if other criteria are met */
+            DEBUGF("  :p pts>=next pts\n");
+        }
+        if (time >= nextpts)
+        {
+            /* Ugh */
+            DEBUGF("  :( time>=nextpts\n");
+        }
+    }
+#endif
+
+    return pos;
+}
+
+static bool prepare_image(uint32_t time)
+{
+    struct stream_scan sk;
+    int tries;
+    int result;
+
+    if (!str_send_msg(&video_str, STREAM_NEEDS_SYNC, time))
+    {
+        DEBUGF("Image was ready\n");
+        return true; /* Should already have the image */
+    }
+
+#ifdef HAVE_ADJUSTABLE_CPU_FREQ
+    rb->cpu_boost(true); /* No interference with trigger_cpu_boost */
+#endif
+
+    str_send_msg(&video_str, STREAM_RESET, 0);
+
+    sk.pos = parser_can_seek() ?
+                mpeg_parser_seek_PTS(time, video_str.id) : 0;
+    sk.len = sk.pos;
+    sk.dir = SSCAN_REVERSE;
+
+    tries = 1;
+try_again:
+
+    if (mpeg_parser_scan_start_code(&sk, MPEG_START_GOP))
+    {
+        DEBUGF("GOP found at: %ld\n", sk.pos);
+
+        unsigned id = mpeg_parser_scan_pes(&sk);
+
+        if (id != video_str.id && sk.pos > 0)
+        {
+            /* Not part of our stream */
+            DEBUGF("  wrong stream: 0x%02x\n", id);
+            goto try_again;
+        }
+
+        /* This will hit the PES header since it's known to be there */
+        uint32_t pts = mpeg_parser_scan_pts(&sk, id);
+
+        if (pts == INVALID_TIMESTAMP || pts > time)
+        {
+            DEBUGF("  wrong timestamp: %u\n", (unsigned)pts);
+            goto try_again;
+        }
+    }
+
+    str_parser.parms.sd.time = time;
+    str_parser.parms.sd.sk.pos = MAX(sk.pos, 0);
+    str_parser.parms.sd.sk.len = 1024*1024;
+    str_parser.parms.sd.sk.dir = SSCAN_FORWARD;
+
+    DEBUGF("thumb pos:%ld len:%ld\n", str_parser.parms.sd.sk.pos,
+           str_parser.parms.sd.sk.len);
+
+    result = str_send_msg(&video_str, STREAM_SYNC,
+                          (intptr_t)&str_parser.parms.sd);
+
+    if (result != STREAM_PERFECT_MATCH)
+    {
+        /* Two tries should be all that is nescessary to find the exact frame
+         * if the first GOP actually started later than the timestamp - the
+         * GOP just prior must then start on or earlier. */
+        if (++tries <= 2)
+            goto try_again;
+    }
+
+#ifdef HAVE_ADJUSTABLE_CPU_FREQ
+    rb->cpu_boost(false);
+#endif
+
+    return result > STREAM_OK;
+}
+
+static void prepare_audio(uint32_t time)
+{
+    off_t pos;
+
+    if (!str_send_msg(&audio_str, STREAM_NEEDS_SYNC, time))
+    {
+        DEBUGF("Audio was ready\n");
+        return;
+    }
+
+    pos = mpeg_parser_seek_PTS(time, audio_str.id);
+    str_send_msg(&audio_str, STREAM_RESET, 0);
+
+    str_parser.parms.sd.time = time;
+    str_parser.parms.sd.sk.pos = pos;
+    str_parser.parms.sd.sk.len = 1024*1024;
+    str_parser.parms.sd.sk.dir = SSCAN_FORWARD;
+
+    str_send_msg(&audio_str, STREAM_SYNC, (intptr_t)&str_parser.parms.sd);
+}
+
+/* This function demuxes the streams and gives the next stream data
+ * pointer.
+ *
+ * STREAM_PM_STREAMING is for operation during playback. If the nescessary
+ * data and worst-case lookahead margin is not available, the stream is
+ * registered for notification when the data becomes available. If parsing
+ * extends beyond the end of the file or the end of stream marker is reached,
+ * STREAM_DATA_END is returned and the stream state changed to SSTATE_EOS.
+ *
+ * STREAM_PM_RANDOM_ACCESS is for operation when not playing such as seeking.
+ * If the file cache misses for the current position + lookahead, it will be
+ * loaded from disk. When the specified limit is reached, STREAM_DATA_END is
+ * returned.
+ *
+ * The results from one mode may be used as input to the other. Random access
+ * requires cooperation amongst threads to avoid evicting another stream's
+ * data.
+ */
+static int parse_demux(struct stream *str, enum stream_parse_mode type)
+{
+    #define INC_BUF(offset) \
+        ({ off_t _o = (offset);           \
+           str->hdr.win_right += _o;      \
+           if ((p += _o) >= disk_buf.end) \
+                p -= disk_buf.size; })
+
+    static const int mpeg1_skip_table[16] =
+        { 0, 0, 4, 9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+
+    uint8_t *p = str->curr_packet_end;
+
+    str->pkt_flags = 0;
+
+    while (1)
+    {
+        uint8_t *header;
+        unsigned id;
+        ssize_t length, bytes;
+
+        switch (type)
+        {
+        case STREAM_PM_STREAMING:
+            /* Has the end been reached already? */
+            if (str->state == SSTATE_END)
+                return STREAM_DATA_END;
+
+            /* Are we at the end of file? */
+            if (str->hdr.win_left >= disk_buf.filesize)
+            {
+                str_end_of_stream(str);
+                return STREAM_DATA_END;
+            }
+
+            if (!disk_buf_is_data_ready(&str->hdr, MIN_BUFAHEAD))
+            {
+                /* This data range is not buffered yet - register stream to
+                 * be notified when it becomes available. Stream is obliged
+                 * to enter a TSTATE_DATA state if it must wait. */
+                int res = str_next_data_not_ready(str);
+
+                if (res != STREAM_OK)
+                    return res;
+            }
+            break;
+            /* STREAM_PM_STREAMING: */
+
+        case STREAM_PM_RANDOM_ACCESS:
+            str->hdr.pos = disk_buf_lseek(str->hdr.pos, SEEK_SET);
+
+            if (str->hdr.pos < 0 || str->hdr.pos >= str->hdr.limit ||
+                disk_buf_getbuffer(MIN_BUFAHEAD, &p, NULL, NULL) <= 0)
+            {
+                str_end_of_stream(str);
+                return STREAM_DATA_END;
+            }
+
+            str->state = SSTATE_SYNC;
+            str->hdr.win_left = str->hdr.pos;
+            str->curr_packet = NULL;
+            str->curr_packet_end = p;
+            break;
+            /* STREAM_PM_RANDOM_ACCESS: */
+        }
+
+        if (str->state == SSTATE_SYNC)
+        {
+            /* Scanning for start code */
+            if (!CMP_3_CONST(p, PACKET_START_CODE_PREFIX))
+            {
+                INC_BUF(1);
+                continue;
+            }
+        }
+
+        /* Found a start code - enter parse state */
+        str->state = SSTATE_PARSE;
+
+        /* Pack header, skip it */
+        if (CMP_4_CONST(p, PACK_START_CODE))
+        {
+            /* Max lookahead: 14 */
+            if ((p[4] & 0xc0) == 0x40)      /* mpeg-2 */
+            {
+                /* Max delta: 14 + 7 = 21 */
+                /* Skip pack header and any stuffing bytes*/
+                bytes = 14 + (p[13] & 7);
+            }
+            else if ((p[4] & 0xf0) == 0x20) /* mpeg-1 */
+            {
+                bytes = 12;
+            }
+            else                            /* unknown - skip it */
+            {
+                DEBUGF("weird pack header!\n");
+                bytes = 5;
+            }
+
+            INC_BUF(bytes);
+        }
+
+        /* System header, parse and skip it - 6 bytes + size */
+        if (CMP_4_CONST(p, SYSTEM_HEADER_START_CODE))
+        {
+            /* Skip start code */
+            /* Max Delta = 65535 + 6 = 65541 */
+            bytes = 6 + ((p[4] << 8) | p[5]);
+            INC_BUF(bytes);
+        }
+
+        /* Packet header, parse it */
+        if (!CMP_3_CONST(p, PACKET_START_CODE_PREFIX))
+        {
+            /* Problem? Meh...probably not but just a corrupted section.
+             * Try to resync the parser which will probably succeed. */
+            DEBUGF("packet start code prefix not found: 0x%02x\n"
+                   "  wl:%lu wr:%lu\n"
+                   "  p:%p cp:%p cpe:%p\n"
+                   "  dbs:%p dbe:%p dbt:%p\n",
+                   str->id, str->hdr.win_left, str->hdr.win_right,
+                   p, str->curr_packet, str->curr_packet_end,
+                   disk_buf.start, disk_buf.end, disk_buf.tail);
+            str->state = SSTATE_SYNC;
+            INC_BUF(1); /* Next byte - this one's no good */
+            continue;
+        }
+
+        /* We retrieve basic infos */
+        /* Maximum packet length: 6 + 65535 = 65541 */
+        id = p[3];
+        length = ((p[4] << 8) | p[5]) + 6;
+
+        if (id != str->id)
+        {
+            switch (id)
+            {
+            case MPEG_STREAM_PROGRAM_END:
+                /* end of stream */
+                str_end_of_stream(str);
+                DEBUGF("MPEG program end: 0x%02x\n", str->id);
+                return STREAM_DATA_END;
+            case MPEG_STREAM_PACK_HEADER:
+            case MPEG_STREAM_SYSTEM_HEADER:
+                /* These shouldn't be here - no increment or resync
+                 * since we'll pick it up above. */
+                continue;
+            default:
+                /* It's not the packet we're looking for, skip it */
+                INC_BUF(length);
+                continue;
+            }
+        }
+
+        /* Ok, it's our packet */
+        header = p;
+
+        if ((header[6] & 0xc0) == 0x80) /* mpeg2 */
+        {
+            /* Max Lookahead: 18         */
+            /* Min length: 9             */
+            /* Max length: 9 + 255 = 264 */
+            length = 9 + header[8];
+
+            /* header points to the mpeg2 pes header */
+            if ((header[7] & 0x80) != 0)
+            {
+                /* header has a pts */
+                uint32_t pts = read_pts(header, 9);
+
+                if (pts != INVALID_TIMESTAMP)
+                {
+                    str->pts = pts;
+#if 0
+                   /* DTS isn't used for anything since things just get
+                      decoded ASAP but keep the code around */
+                    if (STREAM_IS_VIDEO(id))
+                    {
+                        /* Video stream - header may have a dts as well */
+                        str->dts = pts;
+
+                        if (header[7] & 0x40) != 0x00)
+                        {
+                            pts = read_pts(header, 14);
+                            if (pts != INVALID_TIMESTAMP)
+                                str->dts = pts;
+                        }
+                    }
+#endif
+                    str->pkt_flags |= PKT_HAS_TS;
+                }
+            }
+        }
+        else                            /* mpeg1 */
+        {
+            /* Max lookahead: 24 + 2 + 9 = 35 */
+            /* Max len_skip: 24 + 2 = 26      */
+            /* Min length: 7                  */
+            /* Max length: 24 + 2 + 9 = 35    */
+            off_t len_skip;
+            uint8_t * ptsbuf;
+
+            length = 7;
+
+            while (header[length - 1] == 0xff)
+            {
+                if (++length > 23)
+                {
+                    DEBUGF("Too much stuffing" );
+                    break;
+                }
+            }
+
+            if ((header[length - 1] & 0xc0) == 0x40)
+                length += 2;
+
+            len_skip = length;
+            length += mpeg1_skip_table[header[length - 1] >> 4];
+
+            /* Header points to the mpeg1 pes header */
+            ptsbuf = header + len_skip;
+
+            if ((ptsbuf[-1] & 0xe0) == 0x20 && TS_CHECK_MARKERS(ptsbuf, -1))
+            {
+                /* header has a pts */
+                uint32_t pts = read_pts(ptsbuf, -1);
+
+                if (pts != INVALID_TIMESTAMP)
+                {
+                    str->pts = pts;
+#if 0
+                    /* DTS isn't used for anything since things just get
+                       decoded ASAP but keep the code around */
+                    if (STREAM_IS_VIDEO(id))
+                    {
+                        /* Video stream - header may have a dts as well */
+                        str->dts = pts;
+
+                        if (ptsbuf[-1] & 0xf0) == 0x30)
+                        {
+                            pts = read_pts(ptsbuf, 4);
+
+                            if (pts != INVALID_TIMESTAMP)
+                                str->dts = pts;
+                        }
+                    }
+#endif
+                    str->pkt_flags |= PKT_HAS_TS;
+                }
+            }
+        }
+
+        p += length;
+        /* Max bytes: 6 + 65535 - 7 = 65534 */
+        bytes = 6 + (header[4] << 8) + header[5] - length;
+
+        str->curr_packet = p;
+        str->curr_packet_end = p + bytes;
+        str->hdr.win_left = str->hdr.win_right + length;
+        str->hdr.win_right = str->hdr.win_left + bytes;
+
+        if (str->hdr.win_right > disk_buf.filesize)
+        {
+            /* No packet that exceeds end of file can be valid */
+            str_end_of_stream(str);
+            return STREAM_DATA_END;
+        }
+
+        return STREAM_OK;
+    } /* end while */
+
+    #undef INC_BUF
+}
+
+/* This simply reads data from the file one page at a time and returns a
+ * pointer to it in the buffer. */
+static int parse_elementary(struct stream *str, enum stream_parse_mode type)
+{
+    uint8_t *p;
+    ssize_t len = 0;
+
+    str->pkt_flags = 0;
+
+    switch (type)
+    {
+    case STREAM_PM_STREAMING:
+        /* Has the end been reached already? */
+        if (str->state == SSTATE_END)
+            return STREAM_DATA_END;
+
+        /* Are we at the end of file? */
+        if (str->hdr.win_left >= disk_buf.filesize)
+        {
+            str_end_of_stream(str);
+            return STREAM_DATA_END;
+        }
+
+        if (!disk_buf_is_data_ready(&str->hdr, MIN_BUFAHEAD))
+        {
+            /* This data range is not buffered yet - register stream to
+             * be notified when it becomes available. Stream is obliged
+             * to enter a TSTATE_DATA state if it must wait. */
+            int res = str_next_data_not_ready(str);
+
+            if (res != STREAM_OK)
+                return res;
+        }
+
+        len = DISK_BUF_PAGE_SIZE;
+
+        if ((size_t)(str->hdr.win_right + len) > (size_t)disk_buf.filesize)
+            len = disk_buf.filesize - str->hdr.win_right;
+
+        if (len <= 0)
+        {
+            str_end_of_stream(str);
+            return STREAM_DATA_END;
+        }
+
+        p = str->curr_packet_end;
+        break;
+        /* STREAM_PM_STREAMING: */
+
+    case STREAM_PM_RANDOM_ACCESS:
+        str->hdr.pos = disk_buf_lseek(str->hdr.pos, SEEK_SET);
+        len = disk_buf_getbuffer(DISK_BUF_PAGE_SIZE, &p, NULL, NULL);
+
+        if (len <= 0 || str->hdr.pos < 0 || str->hdr.pos >= str->hdr.limit)
+        {
+            str_end_of_stream(str);
+            return STREAM_DATA_END;
+        }
+        break;
+        /* STREAM_PM_RANDOM_ACCESS: */
+    }
+
+    str->state = SSTATE_PARSE;
+    str->curr_packet = p;
+    str->curr_packet_end = p + len;
+    str->hdr.win_left = str->hdr.win_right;
+    str->hdr.win_right = str->hdr.win_left + len;
+
+    return STREAM_OK;
+}
+
+intptr_t parser_send_video_msg(long id, intptr_t data)
+{
+    intptr_t retval = 0;
+
+    if (video_str.thread != NULL && disk_buf.in_file >= 0)
+    {
+        /* Hook certain messages since they involve multiple operations
+         * behind the scenes */
+        switch (id)
+        {
+        case VIDEO_DISPLAY_SHOW:
+            if (data != 0 && stream_status() != STREAM_PLAYING)
+            {   /* Only prepare image if showing and not playing */
+                prepare_image(str_parser.last_seek_time);
+            }
+            break;
+
+        case VIDEO_PRINT_FRAME:
+        case VIDEO_PRINT_THUMBNAIL:
+            if (stream_status() == STREAM_PLAYING)
+                break; /* Prepare image if not playing */
+
+            if (!prepare_image(str_parser.last_seek_time))
+                return false; /* Preparation failed */
+
+            /* Image ready - pass message to video thread */
+            break;
+        }
+
+        retval = str_send_msg(&video_str, id, data);
+    }
+
+    return retval;
+}
+
+/* Seek parser to the specified time and return absolute time.
+ * No actual hard stuff is performed here. That's done when streaming is
+ * about to begin or something from the current position is requested */
+uint32_t parser_seek_time(uint32_t time)
+{
+    if (!parser_can_seek())
+        time = 0;
+    else if (time > str_parser.duration)
+        time = str_parser.duration;
+
+    str_parser.last_seek_time = time + str_parser.start_pts;
+    return str_parser.last_seek_time;
+}
+
+void parser_prepare_streaming(void)
+{
+    struct stream_window sw;
+
+    DEBUGF("parser_prepare_streaming\n");
+
+    /* Prepare initial video frame */
+    prepare_image(str_parser.last_seek_time);
+
+    /* Sync audio stream */
+    if (audio_str.start_pts != INVALID_TIMESTAMP)
+        prepare_audio(str_parser.last_seek_time);
+
+    /* Prequeue some data and set buffer window */
+    if (!stream_get_window(&sw))
+        sw.left = sw.right = disk_buf.filesize;
+
+    DEBUGF("  swl:%ld swr:%ld\n", sw.left, sw.right);
+
+    if (sw.right > disk_buf.filesize - 4*MIN_BUFAHEAD)
+        sw.right = disk_buf.filesize - 4*MIN_BUFAHEAD;
+
+    disk_buf_prepare_streaming(sw.left,
+        sw.right - sw.left + 4*MIN_BUFAHEAD);
+}
+
+int parser_init_stream(void)
+{
+    if (disk_buf.in_file < 0)
+        return STREAM_ERROR;
+
+    /* TODO: Actually find which streams are available */
+    audio_str.id = MPEG_STREAM_AUDIO_FIRST;
+    video_str.id = MPEG_STREAM_VIDEO_FIRST;
+
+    /* Try to pull a video PES - if not found, try video init anyway which
+     * should succeed if it really is a video-only stream */
+    video_str.hdr.pos = 0;
+    video_str.hdr.limit = 256*1024;
+    
+    if (parse_demux(&video_str, STREAM_PM_RANDOM_ACCESS) == STREAM_OK)
+    {
+        /* Found a video packet - assume transport stream */
+        str_parser.format = STREAM_FMT_MPEG_TS;
+        str_parser.next_data = parse_demux;
+    }
+    else
+    {
+        /* No PES element found - assume video elementary stream */
+        str_parser.format = STREAM_FMT_MPV;
+        str_parser.next_data = parse_elementary;
+    }
+
+    if (!init_video_info())
+    {
+        /* Cannot determine video size, etc. */
+        return STREAM_UNSUPPORTED;
+    }
+
+    if (str_parser.format == STREAM_FMT_MPEG_TS)
+    {
+        /* Initalize start_pts and end_pts with the length (in 45kHz units) of
+         * the movie. INVALID_TIMESTAMP if the time could not be determined */
+        init_times(&audio_str);
+        init_times(&video_str);
+
+        if (video_str.start_pts == INVALID_TIMESTAMP)
+        {
+            /* Must have video at least */
+            return STREAM_UNSUPPORTED;
+        }
+
+        str_parser.flags |= STREAMF_CAN_SEEK;
+
+        if (audio_str.start_pts != INVALID_TIMESTAMP)
+        {
+            /* Overall duration is maximum span */
+            str_parser.start_pts = MIN(audio_str.start_pts, video_str.start_pts);
+            str_parser.end_pts = MAX(audio_str.end_pts, video_str.end_pts);
+
+            /* Audio will be part of playback pool */
+            stream_add_stream(&audio_str);
+        }
+        else
+        {
+            /* No audio stream - use video only */
+            str_parser.start_pts = video_str.start_pts;
+            str_parser.end_pts = video_str.end_pts;
+        }
+    }
+    else
+    {
+        /* There's no way to handle times on this without a full file
+         * scan */
+        audio_str.start_pts = INVALID_TIMESTAMP;
+        audio_str.end_pts = INVALID_TIMESTAMP;
+        video_str.start_pts = 0;
+        video_str.end_pts = INVALID_TIMESTAMP;
+        str_parser.start_pts = 0;
+        str_parser.end_pts = INVALID_TIMESTAMP;
+    }
+
+    /* Add video to playback pool */
+    stream_add_stream(&video_str);
+
+    /* Cache duration - it's used very often */
+    str_parser.duration = str_parser.end_pts - str_parser.start_pts;
+
+    DEBUGF("Movie info:\n"
+           "  size:%dx%d\n"
+           "  start:%u\n"
+           "  end:%u\n"
+           "  duration:%u\n",
+           str_parser.dims.w, str_parser.dims.h,
+           (unsigned)str_parser.start_pts,
+           (unsigned)str_parser.end_pts,
+           (unsigned)str_parser.duration);
+
+    return STREAM_OK;
+}
+
+void parser_close_stream(void)
+{
+    stream_remove_streams();
+    parser_init_state();
+}
+
+bool parser_init(void)
+{
+    parser_init_state();
+    return true;
+}