Generally speaking, there are two types of v4l2 devices [1]:
1) devices that support a standard, like PAL or NTFS (tv cards, for example). For
this class of devices the framerate is fixed by the standard (for example PAL uses
25 fps) and the v4l2 driver cannot usually negotiate a different framerate (unless
it can skip frames on the driver side, to save I/O bandwidth).
2) devices for which the notion of standard does not make sense (webcams, for example).
For these devices it is usually possibile to request a desidered framerate.
In either case, the desidered frame rate can be requested when the VIDIOC_G_PARM
ioctl returns the V4L2_CAP_TIMEPERFRAME flag in the capability field.
Currently the code does not check for V4L2_CAP_TIMEPERFRAME and supports only the
second category of devices, returning a time per frame of 0/0 for devices in the
first group that do not permit to negotiate the framerate.
This patch adds support to read the correct framerate in all cases.
[1] http://linuxtv.org/downloads/v4l-dvb-apis/standard.html
Signed-off-by: Stefano Sabatini <stefasab@gmail.com>
Since the user is expected to choose the standard by name (with -standard
option), add the possibility to list all the supported standards.
Signed-off-by: Stefano Sabatini <stefasab@gmail.com>
Because libavdevice/v4l2 is a demuxer, it makes sense to look for
decoders instead of encoders when listing the formats supported by the
device.
Signed-off-by: Stefano Sabatini <stefasab@gmail.com>
Make device_try_init() return an error value, and allow to properly
report errors which are not due to a wrong pixel/codec configuration.
In particular, report intelligible feedback in case of busy device.
* commit '90cfc084e3e6d37ab88fc96a95f0401d8e8b4cd1':
avpacket: free side data in av_free_packet().
v4l2: do not assert on a value received from outside of Libav
v4l2: set the average framerate instead of codec timebase.
Conflicts:
libavcodec/avpacket.c
libavdevice/v4l2.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* commit '124134e42455763b28cc346fed1d07017a76e84e':
avopt: Store defaults for AV_OPT_TYPE_CONST in the i64 union member
Conflicts:
libavcodec/aacenc.c
libavcodec/libopenjpegenc.c
libavcodec/options_table.h
libavdevice/bktr.c
libavdevice/v4l2.c
libavdevice/x11grab.c
libavfilter/af_amix.c
libavfilter/vf_drawtext.c
libavformat/movenc.c
libavformat/options_table.h
libavutil/opt.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
The cpia video decoder is intended to be used with the v4l2 demuxer.
There are some small changes to the v4l2 demuxer to support the
variable frame length of the format.
Fixes ticket #1537
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
* qatar/master:
MS Screen 1 decoder
aacdec: Fix popping channel layouts.
av_gettime: support Win32 without gettimeofday()
Use av_gettime() in various places
Move av_gettime() to libavutil
dct-test: use emms_c() from libavutil instead of duplicating it
mov: fix operator precedence bug
mathematics.h: remove a couple of math defines
Remove unnecessary inclusions of [sys/]time.h
lavf: remove unnecessary inclusions of unistd.h
bfin: libswscale: add const where appropriate to fix warnings
bfin: libswscale: remove unnecessary #includes
udp: Properly check for invalid sockets
tcp: Check the return value from getsockopt
network: Use av_strerror for getting error messages
udp: Properly print error from getnameinfo
mmst: Use AVUNERROR() to convert error codes to the right range for strerror
network: Pass pointers of the right type to get/setsockopt/ioctlsocket on windows
rtmp: Reduce the number of idle posts sent by sleeping 50ms
Conflicts:
Changelog
configure
libavcodec/aacdec.c
libavcodec/allcodecs.c
libavcodec/avcodec.h
libavcodec/dct-test.c
libavcodec/version.h
libavformat/riff.c
libavformat/udp.c
libavutil/Makefile
libswscale/bfin/yuv2rgb_bfin.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
This reverts commit 0efd48dfd1.
Reason for the revert is that the code seems based on some
misunderstanding on how the code works.
Conflicts:
libavdevice/v4l2.c
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
* qatar/master: (22 commits)
rv34: frame-level multi-threading
mpegvideo: claim ownership of referenced pictures
aacsbr: prevent out of bounds memcpy().
ipmovie: fix pts for CODEC_ID_INTERPLAY_DPCM
sierravmd: fix audio pts
bethsoftvideo: Use bytestream2 functions to prevent buffer overreads.
bmpenc: support for PIX_FMT_RGB444
swscale: fix crash in fast_bilinear code when compiled with -mred-zone.
swscale: specify register type.
rv34: use get_bits_left()
avconv: reinitialize the filtergraph on resolution change.
vsrc_buffer: error on changing frame parameters.
avconv: fix -copyinkf.
fate: Update file checksums after the mov muxer change in a78dbada55
movenc: Don't store a nonzero creation time if nothing was set by the caller
bmpdec: support for rgb444 with bitfields compression
rgb2rgb: allow conversion for <15 bpp
doc: fix stray reference to FFmpeg
v4l2: use C99 struct initializer
v4l2: poll the file descriptor
...
Conflicts:
avconv.c
libavcodec/aacsbr.c
libavcodec/bethsoftvideo.c
libavcodec/kmvc.c
libavdevice/v4l2.c
libavfilter/vsrc_buffer.c
libswscale/swscale_unscaled.c
libswscale/x86/input.asm
tests/ref/acodec/alac
tests/ref/acodec/pcm_s16be
tests/ref/acodec/pcm_s24be
tests/ref/acodec/pcm_s32be
tests/ref/acodec/pcm_s8
tests/ref/lavf/mov
tests/ref/vsynth1/dnxhd_1080i
tests/ref/vsynth1/mpeg4
tests/ref/vsynth1/qtrle
tests/ref/vsynth1/svq1
tests/ref/vsynth2/dnxhd_1080i
tests/ref/vsynth2/mpeg4
tests/ref/vsynth2/qtrle
tests/ref/vsynth2/svq1
Merged-by: Michael Niedermayer <michaelni@gmx.at>
