From 6adf3c2499f81e9254e160e04ce3c821bd47938d Mon Sep 17 00:00:00 2001 From: Lyon Wang Date: Tue, 12 May 2015 15:47:33 +0800 Subject: [PATCH] h263parse: fix custom picture format (CPFMT) parsing In the H263 spec, CPFMT is present only if the use of a custom picture format is signalled in PLUSEPTYPE and UFEP is "001", so we need to check params->format and only if the value is 6 (custom source format) the CPFMT should be read, otherwise it's not present and wrong data will be parsed. When reading the CPFMT, the width and height were not calculated correctly (wrong bitmask). https://bugzilla.gnome.org//show_bug.cgi?id=749253 --- gst/videoparsers/h263parse.c | 57 ++++++++++++++++++++++++++++---------------- 1 file changed, 37 insertions(+), 20 deletions(-) diff --git a/gst/videoparsers/h263parse.c b/gst/videoparsers/h263parse.c index d794f7a..98a30e7 100644 --- a/gst/videoparsers/h263parse.c +++ b/gst/videoparsers/h263parse.c @@ -271,29 +271,46 @@ gst_h263_parse_get_params (H263Params * params, GstBuffer * buffer, } if (ufep == 1) { - guint32 cpfmt = 0; + if (params->format == 6) { + /* A fixed length codeword of 23 bits that is present only if the use of + * a custom picture format is signalled in PLUSPTYPE and UFEP is 001 */ + guint32 cpfmt = 0; - /* 5.1.5 CPFMT : Custom Picture Format (23 bits) */ - if (!gst_bit_reader_get_bits_uint32 (&br, &cpfmt, 23)) - goto more; - if (!(cpfmt & 0x200)) { - GST_WARNING ("Corrupted CPFMT (0x%x)", cpfmt); - goto beach; - } - temp8 = cpfmt >> 19; - params->width = (((cpfmt >> 10) & 0x1f) + 1) * 4; - params->height = ((cpfmt & 0x1f) + 1) * 4; - - if (temp8 == 0xf) { - guint32 epar = 0; - /* 5.1.6 EPAR : Extended Pixel Aspect Ratio (16bits) */ - if (!gst_bit_reader_get_bits_uint32 (&br, &epar, 16)) + /* 5.1.5 CPFMT : Custom Picture Format (23 bits) */ + if (!gst_bit_reader_get_bits_uint32 (&br, &cpfmt, 23)) goto more; - params->parnum = epar >> 8; - params->pardenom = epar & 0xf; + if (!(cpfmt & 0x200)) { + GST_WARNING ("Corrupted CPFMT (0x%x)", cpfmt); + goto beach; + } + temp8 = cpfmt >> 19; + /* Bits 5-13: Picture Width Indication: Range [0, ... , 511]; + * Number of pixels per line = (PWI + 1) * 4 */ + params->width = (((cpfmt >> 10) & 0x1ff) + 1) * 4; + /* Bits 15-23 Picture Height Indication: Range [1, ... , 288]; + * Number of lines = PHI * 4 */ + params->height = (cpfmt & 0x1ff) * 4; + + if (temp8 == 0xf) { + guint32 epar = 0; + /* 5.1.6 EPAR : Extended Pixel Aspect Ratio (16bits) */ + if (!gst_bit_reader_get_bits_uint32 (&br, &epar, 16)) + goto more; + params->parnum = epar >> 8; + params->pardenom = epar & 0xf; + } else { + params->parnum = partable[temp8][0]; + params->pardenom = partable[temp8][1]; + } } else { - params->parnum = partable[temp8][0]; - params->pardenom = partable[temp8][1]; + /* Fill in width/height based on format */ + params->width = sizetable[params->format][0]; + params->height = sizetable[params->format][1]; + GST_DEBUG (" Picture width x height: %d x %d", + params->width, params->height); + /* Fill in default Pixel aspect ratios */ + params->parnum = 12; + params->pardenom = 11; } if (params->custompcfpresent) { -- 2.7.4