libmpdemux: add back demux_mpg

Apparently this was needed for good DVD playback.

This demuxer has been removed in 1fde09db6f4ce. All code added comes
from the revision before that. Some other bits have been removed in
later commits, and are added back as well.

Usage of memalign() is replaced by av_malloc(). As far as I can tell,
this memory is never free'd or reallocated, so no calls to av_free()
have been added.

The code re-added to video.c is plain horrible, full of code
duplication, full of demuxer/codecs specifics, but apparently needed.

Unrelated to re-adding the demuxer, re-add one codepath for
DEMUXER_TYPE_TV, which was accidentally removed in the same commit
demux_mpg was removed.

The closed captions decoder is not re-added.

1 files changed, 50 insertions, 1 deletions

diff --git a/libmpdemux/demuxer.c b/libmpdemux/demuxer.c
index ce425751f9..2372e10843 100644
--- a/libmpdemux/demuxer.c
+++ b/libmpdemux/demuxer.c
@@ -63,6 +63,12 @@ extern const demuxer_desc_t demuxer_desc_gif;
 extern const demuxer_desc_t demuxer_desc_lavf;
 extern const demuxer_desc_t demuxer_desc_lavf_preferred;
 extern const demuxer_desc_t demuxer_desc_mng;
+extern const demuxer_desc_t demuxer_desc_mpeg_ps;
+extern const demuxer_desc_t demuxer_desc_mpeg_pes;
+extern const demuxer_desc_t demuxer_desc_mpeg_gxf;
+extern const demuxer_desc_t demuxer_desc_mpeg_es;
+extern const demuxer_desc_t demuxer_desc_mpeg4_es;
+extern const demuxer_desc_t demuxer_desc_h264_es;
 
 /* Please do not add any new demuxers here. If you want to implement a new
  * demuxer, add it to libavformat, except for wrappers around external
@@ -88,6 +94,12 @@ const demuxer_desc_t *const demuxer_list[] = {
 #ifdef CONFIG_MNG
     &demuxer_desc_mng,
 #endif
+    &demuxer_desc_mpeg_ps,
+    &demuxer_desc_mpeg_pes,
+    &demuxer_desc_mpeg_gxf,
+    &demuxer_desc_mpeg_es,
+    &demuxer_desc_mpeg4_es,
+    &demuxer_desc_h264_es,
     /* Please do not add any new demuxers here. If you want to implement a new
      * demuxer, add it to libavformat, except for wrappers around external
      * libraries and demuxers requiring binary support. */
@@ -685,6 +697,43 @@ int demux_read_data(demux_stream_t *ds, unsigned char *mem, int len)
     return bytes;
 }
 
+/**
+ * \brief read data until the given 3-byte pattern is encountered, up to maxlen
+ * \param mem memory to read data into, may be NULL to discard data
+ * \param maxlen maximum number of bytes to read
+ * \param read number of bytes actually read
+ * \param pattern pattern to search for (lowest 8 bits are ignored)
+ * \return whether pattern was found
+ */
+int demux_pattern_3(demux_stream_t *ds, unsigned char *mem, int maxlen,
+                    int *read, uint32_t pattern)
+{
+    register uint32_t head = 0xffffff00;
+    register uint32_t pat = pattern & 0xffffff00;
+    int total_len = 0;
+    do {
+        register unsigned char *ds_buf = &ds->buffer[ds->buffer_size];
+        int len = ds->buffer_size - ds->buffer_pos;
+        register long pos = -len;
+        if (unlikely(pos >= 0)) { // buffer is empty
+            ds_fill_buffer(ds);
+            continue;
+        }
+        do {
+            head |= ds_buf[pos];
+            head <<= 8;
+        } while (++pos && head != pat);
+        len += pos;
+        if (total_len + len > maxlen)
+            len = maxlen - total_len;
+        len = demux_read_data(ds, mem ? &mem[total_len] : NULL, len);
+        total_len += len;
+    } while ((head != pat || total_len < 3) && total_len < maxlen && !ds->eof);
+    if (read)
+        *read = total_len;
+    return total_len >= 3 && head == pat;
+}
+
 void ds_free_packs(demux_stream_t *ds)
 {
     demux_packet_t *dp = ds->first;
@@ -938,7 +987,7 @@ struct demuxer *demux_open_withparams(struct MPOpts *opts,
     // format, instead of reyling on libav to auto-detect the stream's format
     // correctly.
     switch (file_format) {
-    case DEMUXER_TYPE_MPEG_PS:
+    //case DEMUXER_TYPE_MPEG_PS:
     case DEMUXER_TYPE_MPEG_TS:
     case DEMUXER_TYPE_Y4M:
     case DEMUXER_TYPE_NSV: