diff options
| -rw-r--r-- | ext/jpeg/gstjpegdec.c | 50 | ||||
| -rw-r--r-- | ext/jpeg/gstjpegdec.h | 5 |
2 files changed, 45 insertions, 10 deletions
diff --git a/ext/jpeg/gstjpegdec.c b/ext/jpeg/gstjpegdec.c index 606f9a295..d9e122663 100644 --- a/ext/jpeg/gstjpegdec.c +++ b/ext/jpeg/gstjpegdec.c @@ -414,6 +414,7 @@ gst_jpeg_dec_parse_image_data (GstJpegDec * dec) { guint8 *start, *data, *end; guint size; + gboolean resync; size = GST_BUFFER_SIZE (dec->tempbuf); start = GST_BUFFER_DATA (dec->tempbuf); @@ -424,12 +425,14 @@ gst_jpeg_dec_parse_image_data (GstJpegDec * dec) GST_DEBUG ("Parsing jpeg image data (%u bytes)", size); - /* skip start marker */ - data += 2; + GST_DEBUG ("Parse state: offset=%d, resync=%d, entropy len=%d", + dec->parse_offset, dec->parse_resync, dec->parse_entropy_len); + + /* resume from state offset (also skips start marker) */ + data += (dec->parse_offset ? dec->parse_offset : 2); while (1) { guint frame_len; - gboolean resync; /* do we need to resync? */ resync = (*data != 0xff); @@ -441,28 +444,33 @@ gst_jpeg_dec_parse_image_data (GstJpegDec * dec) ++data; if (G_UNLIKELY (*data != 0xff)) { GST_DEBUG ("at end of input and no next marker found, need more data"); - return 0; + goto need_more_data; } } + /* may have marker, but could have been resyncng */ + resync = resync || dec->parse_resync; /* Skip over extra 0xff */ while (*data == 0xff && data < end) ++data; /* enough bytes left for marker? (we need 0xNN after the 0xff) */ if (data >= end) { GST_DEBUG ("at end of input and no EOI marker found, need more data"); - return 0; + goto need_more_data1; } if (*data == 0xd9) { GST_DEBUG ("0x%08" G_GINT64_MODIFIER "x: EOI marker", (gint64) (data - start)); + /* clear parse state */ + dec->parse_resync = FALSE; + dec->parse_offset = 0; return (data - start + 1); } if (*data >= 0xd0 && *data <= 0xd7) frame_len = 0; else if (data >= end - 2) - return 0; + goto need_more_data1; else frame_len = GST_READ_UINT16_BE (data + 1); GST_DEBUG ("0x%08" G_GINT64_MODIFIER "x: tag %02x, frame_len=%u", @@ -478,22 +486,26 @@ gst_jpeg_dec_parse_image_data (GstJpegDec * dec) /* theoretically we could have lost sync and not really need more * data, but that's just tough luck and a broken image then */ GST_DEBUG ("at end of input and no EOI marker found, need more data"); - return 0; + goto need_more_data1; } if (gst_jpeg_dec_parse_tag_has_entropy_segment (*data)) { guint8 *d2 = data + 1 + frame_len; - guint eseglen = 0; + guint eseglen = dec->parse_entropy_len; GST_DEBUG ("0x%08" G_GINT64_MODIFIER "x: finding entropy segment length", (gint64) (data - start - 1)); while (1) { - if (d2 + eseglen >= end - 1) - return 0; /* need more data */ + if (d2 + eseglen >= end - 1) { + /* need more data */ + dec->parse_entropy_len = eseglen; + goto need_more_data1; + } if (d2[eseglen] == 0xff && d2[eseglen + 1] != 0x00) break; ++eseglen; } + dec->parse_entropy_len = 0; frame_len += eseglen; GST_DEBUG ("entropy segment length=%u => frame_len=%u", eseglen, frame_len); @@ -511,6 +523,21 @@ gst_jpeg_dec_parse_image_data (GstJpegDec * dec) data += 1 + frame_len; } + + /* EXITS */ +need_more_data: + { + dec->parse_offset = data - start; + dec->parse_resync = resync; + return 0; + } +need_more_data1: + { + /* step back one to point at marker */ + dec->parse_offset = (data - start) - 1; + dec->parse_resync = resync; + return 0; + } } /* shamelessly ripped from jpegutils.c in mjpegtools */ @@ -1605,6 +1632,9 @@ gst_jpeg_dec_change_state (GstElement * element, GstStateChange transition) dec->packetized = FALSE; dec->next_ts = 0; dec->discont = TRUE; + dec->parse_offset = 0; + dec->parse_resync = FALSE; + dec->parse_entropy_len = FALSE; gst_segment_init (&dec->segment, GST_FORMAT_UNDEFINED); gst_jpeg_dec_reset_qos (dec); default: diff --git a/ext/jpeg/gstjpegdec.h b/ext/jpeg/gstjpegdec.h index c1e463285..f76089b70 100644 --- a/ext/jpeg/gstjpegdec.h +++ b/ext/jpeg/gstjpegdec.h @@ -103,6 +103,11 @@ struct _GstJpegDec { gint stride; gint inc; + /* parse state */ + gint parse_offset; + gint parse_entropy_len; + gint parse_resync; + /* properties */ gint idct_method; |