FFmpeg

Commit Graph

Author	SHA1	Message	Date
Andreas Rheinhardt	0e66e1b61e	cbs_mpeg2: Decompose Sequence End Sequence End units (or actually, sequence_end_codes) have up until now not been decomposed; in fact due to a bug in cbs_mpeg2_split_fragment they have mostly been treated as part of the preceding unit. So implement decomposing them as preparation for fixing said bug. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>	5 years ago
Andreas Rheinhardt	d9182f04ca	cbs_mpeg2: Fix parsing of picture and slice headers 1. The extra information in slice headers was parsed incorrectly: In the first reading pass to derive the length of the extra information, one should look at bits n, n + 9, n + 18, ... and check whether they equal one (further extra information) or zero (end of extra information), but instead bits n, n + 8, n + 16, ... were inspected. The second pass of reading (where the length is already known and the bytes between the length-determining bits are copied into a buffer) did not record what was in bits n, n + 9, n + 18, ..., presuming they equal one. And during writing, the bytes in the buffer are interleaved with set bits and written. This means that if the detected length of the extra information was greater than the real length, the output was corrupted. Fortunately no sample is known that made use of this mechanism: The extra information in slices is still marked as reserved in the specifications. cbs_mpeg2 is now ready in case this changes. 2. Furthermore, the buffer is now padded and slightly different, but very similar code for reading resp. writing has been replaced by code used for both. This was made possible by a new macro, the equivalent to cbs_h2645's fixed(). 3. These changes also made it possible to remove the extra_bit_slice element from the MPEG2RawSliceHeader structure. Said element was always zero except when the detected length of the extra information was less than the real length. 4. The extra information in picture headers (which uses essentially the same syntax as the extra information in slice headers) has simply been forgotten. This meant that if this extra information was present, it was discarded during reading; and unfortunately writing created invalid bitstreams in this case (an extra_bit_picture - the last set bit of the whole unit - indicated that there would be a further byte of data, although the output didn't contain said data). This has been fixed; both types of extra information are now parsed via the same code and essentially passed through. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>	6 years ago
Andreas Rheinhardt	c2a91645c5	mpeg2_metadata, cbs_mpeg2: Fix handling of colour_description If a sequence display extension is read with colour_description equal to zero, but a user wants to add one or more of the colour_description elements, then the colour_description elements the user did not explicitly request to be set are set to zero and not to the value equal to unknown/unspecified (namely 2). A value of zero is not only inappropriate, but explicitly forbidden. This is fixed by inferring the right default values during the reading process if the elements are absent; moreover, changing any of the colour_description elements to zero is now no longer possible. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>	6 years ago
James Almer	d903c09d9a	avcodec/cbs_mpeg2: fix leak of extra_information_slice buffer in cbs_mpeg2_read_slice_header() cbs_mpeg2_free_slice() calls av_buffer_unref() on extra_information_ref, meaning allocating with av_malloc() was not the intention. Signed-off-by: James Almer <jamrial@gmail.com>	6 years ago
Andreas Rheinhardt	1759a9e5b5	cbs_mpeg2: Correct error codes Up until now, things that are merely unsupported by cbs_mpeg2 have been declared to be invalid input. This has been changed. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>	6 years ago
Andreas Rheinhardt	de58803839	cbs_mpeg2: Fix storage type for frame_centre_*_offset The frame_centre_horizontal/vertical_offset values contained in picture display extensions are actually signed values (i.e. it is possible to indicate that the display device should add black bars/pillars). The files sony-ct3.bs and tcela-6.bits (which are both used in fate tests for mpeg2_metadata) contain picture display extensions; the former even contains a negative frame_centre_vertical_offset. Fortunately, the old code did not damage the picture display extensions when one did a cycle of reading and writing. For the same reason the fate tests needn't be updated either. Furthermore these fields now use the trace output for matrices. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>	6 years ago
Andreas Rheinhardt	9c3f2a8894	cbs_mpeg2: Improve checks for invalid values MPEG-2 contains several elements that mustn't be zero according to the specifications: horizontal/vertical_size_value, aspect_ratio_information, frame_rate_code, the quantiser matrices, the colour_description elements, picture_coding_type, the f_code[r][s] values and quantiser_scale_code. It is now checked that the invalid values don't occur. The colour_description elements are treated specially in this regard: Given that there are files in the wild which use illegal values for the colour_description elements (some of them created by mpeg2_metadata), they will be corrected to the value meaning "unknown" (namely 2) during reading. This has been done in such a way that trace_headers will nevertheless report the original value, together with a message about the fixup. Furthermore, the trace_headers output of user_data has been beautified. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>	6 years ago
Andreas Rheinhardt	cfe4389d47	cbs_mpeg2: Correct and use enum values Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>	6 years ago
Aman Gupta	41ed2c3849	avcodec/cbs: ensure user_data is padded for GBC parsing Fixes crash noticed in the cbs_userdata patchset. ====ERROR: AddressSanitizer: heap-buffer-overflow on address 0x609000026c89 at pc 0x00010725d37b bp 0x7ffeea04e750 sp 0x7ffeea04e748 READ of size 4 at 0x609000026c89 thread T0 #0 0x10725d37a in ff_cbs_read_unsigned get_bits.h:274 #1 0x1072d2767 in ff_cbs_read_a53_user_data cbs_misc_syntax_template.c:119 #2 0x1078251a7 in h264_metadata_filter h264_metadata_bsf.c:595 #3 0x105c1321d in output_packet ffmpeg.c:853 0x609000026c89 is located 1 bytes to the right of 8-byte region [0x609000026c80,0x609000026c88) allocated by thread T0 here: #0 0x10aef08d7 in wrap_posix_memalign (libclang_rt.asan_osx_dynamic.dylib:x86_64h+0x578d7) #1 0x10aca95e6 in av_malloc mem.c:87 #2 0x10ac545fe in av_buffer_allocz buffer.c:72 #3 0x107263b27 in cbs_h264_read_nal_unit cbs_h264_syntax_template.c:722 #4 0x10725b688 in cbs_read_fragment_content cbs.c:155 Signed-off-by: Aman Gupta <aman@tmm1.net>	6 years ago
Mark Thompson	300ef25314	cbs: Add support for array subscripts in trace output This makes the trace output for arrays significantly nicer.	7 years ago
Mark Thompson	ce5870a3a8	cbs: Refcount all the things! This makes it easier for users of the CBS API to get alloc/free right - all subelements use the buffer API so that it's clear how to free them. It also allows eliding some redundant copies: the packet -> fragment copy disappears after this change if the input packet is refcounted, and more codec-specific cases are now possible (but not included in this patch).	7 years ago
Mark Thompson	686e388bbb	lavc: Add coded bitstream read/write support for MPEG-2 (cherry picked from commit `2bc9ba8d3c`) (cherry picked from commit `a41b69b5eb`)	7 years ago
Mark Thompson	a41b69b5eb	cbs_mpeg2: Add support for picture display extension	7 years ago
Mark Thompson	2bc9ba8d3c	lavc: Add coded bitstream read/write support for MPEG-2 Also enable MPEG-2 support in the trace_headers filter.	7 years ago

15 Commits (d15f65c4699de54eafc3b9a8f145cad978666520)