diff options
Diffstat (limited to 'libavformat/dv1394.h')
| -rw-r--r-- | libavformat/dv1394.h | 172 |
1 files changed, 86 insertions, 86 deletions
diff --git a/libavformat/dv1394.h b/libavformat/dv1394.h index 18650cddb6..af37f78082 100644 --- a/libavformat/dv1394.h +++ b/libavformat/dv1394.h @@ -60,21 +60,21 @@ Example 1: To play a raw .DV file: cat foo.DV > /dev/dv1394 - (cat will use write() internally) + (cat will use write() internally) Example 2: static struct dv1394_init init = { - 0x63, (broadcast channel) + 0x63, (broadcast channel) 4, (four-frame ringbuffer) - DV1394_NTSC, (send NTSC video) - 0, 0 (default empty packet rate) + DV1394_NTSC, (send NTSC video) + 0, 0 (default empty packet rate) } - ioctl(fd, DV1394_INIT, &init); + ioctl(fd, DV1394_INIT, &init); - while(1) { - read( <a raw DV file>, buf, DV1394_NTSC_FRAME_SIZE ); - write( <the dv1394 FD>, buf, DV1394_NTSC_FRAME_SIZE ); + while(1) { + read( <a raw DV file>, buf, DV1394_NTSC_FRAME_SIZE ); + write( <the dv1394 FD>, buf, DV1394_NTSC_FRAME_SIZE ); } 2) @@ -104,12 +104,12 @@ frame 0 frame 1 frame 2 frame 3 - *--------------------------------------* + *--------------------------------------* | CLEAR | DV data | DV data | CLEAR | *--------------------------------------* <ACTIVE> - transmission goes in this direction --->>> + transmission goes in this direction --->>> The DV hardware is currently transmitting the data in frame 1. @@ -123,9 +123,9 @@ receive the following values: n_frames = 4 - active_frame = 1 - first_clear_frame = 3 - n_clear_frames = 2 + active_frame = 1 + first_clear_frame = 3 + n_clear_frames = 2 At this point, you should write new DV data into frame 3 and optionally frame 0. Then call DV1394_SUBMIT_FRAMES to inform the device that @@ -170,11 +170,11 @@ ioctl(dv1394_fd, DV1394_GET_STATUS, &status); - if(status.dropped_frames > 0) { - reset_dv1394(); + if(status.dropped_frames > 0) { + reset_dv1394(); } else { for(int i = 0; i < status.n_clear_frames; i++) { - copy_DV_frame(); + copy_DV_frame(); } } } @@ -210,51 +210,51 @@ /* ioctl() commands */ enum { - /* I don't like using 0 as a valid ioctl() */ - DV1394_INVALID = 0, + /* I don't like using 0 as a valid ioctl() */ + DV1394_INVALID = 0, - /* get the driver ready to transmit video. - pass a struct dv1394_init* as the parameter (see below), - or NULL to get default parameters */ - DV1394_INIT, + /* get the driver ready to transmit video. + pass a struct dv1394_init* as the parameter (see below), + or NULL to get default parameters */ + DV1394_INIT, - /* stop transmitting video and free the ringbuffer */ - DV1394_SHUTDOWN, + /* stop transmitting video and free the ringbuffer */ + DV1394_SHUTDOWN, - /* submit N new frames to be transmitted, where - the index of the first new frame is first_clear_buffer, - and the index of the last new frame is - (first_clear_buffer + N) % n_frames */ - DV1394_SUBMIT_FRAMES, + /* submit N new frames to be transmitted, where + the index of the first new frame is first_clear_buffer, + and the index of the last new frame is + (first_clear_buffer + N) % n_frames */ + DV1394_SUBMIT_FRAMES, - /* block until N buffers are clear (pass N as the parameter) - Because we re-transmit the last frame on underrun, there - will at most be n_frames - 1 clear frames at any time */ - DV1394_WAIT_FRAMES, + /* block until N buffers are clear (pass N as the parameter) + Because we re-transmit the last frame on underrun, there + will at most be n_frames - 1 clear frames at any time */ + DV1394_WAIT_FRAMES, - /* capture new frames that have been received, where - the index of the first new frame is first_clear_buffer, - and the index of the last new frame is - (first_clear_buffer + N) % n_frames */ - DV1394_RECEIVE_FRAMES, + /* capture new frames that have been received, where + the index of the first new frame is first_clear_buffer, + and the index of the last new frame is + (first_clear_buffer + N) % n_frames */ + DV1394_RECEIVE_FRAMES, - DV1394_START_RECEIVE, + DV1394_START_RECEIVE, - /* pass a struct dv1394_status* as the parameter (see below) */ - DV1394_GET_STATUS, + /* pass a struct dv1394_status* as the parameter (see below) */ + DV1394_GET_STATUS, }; enum pal_or_ntsc { - DV1394_NTSC = 0, - DV1394_PAL + DV1394_NTSC = 0, + DV1394_PAL }; @@ -262,29 +262,29 @@ enum pal_or_ntsc { /* this is the argument to DV1394_INIT */ struct dv1394_init { - /* DV1394_API_VERSION */ - unsigned int api_version; + /* DV1394_API_VERSION */ + unsigned int api_version; - /* isochronous transmission channel to use */ - unsigned int channel; + /* isochronous transmission channel to use */ + unsigned int channel; - /* number of frames in the ringbuffer. Must be at least 2 - and at most DV1394_MAX_FRAMES. */ - unsigned int n_frames; + /* number of frames in the ringbuffer. Must be at least 2 + and at most DV1394_MAX_FRAMES. */ + unsigned int n_frames; - /* send/receive PAL or NTSC video format */ - enum pal_or_ntsc format; + /* send/receive PAL or NTSC video format */ + enum pal_or_ntsc format; - /* the following are used only for transmission */ + /* the following are used only for transmission */ - /* set these to zero unless you want a - non-default empty packet rate (see below) */ - unsigned long cip_n; - unsigned long cip_d; + /* set these to zero unless you want a + non-default empty packet rate (see below) */ + unsigned long cip_n; + unsigned long cip_d; - /* set this to zero unless you want a - non-default SYT cycle offset (default = 3 cycles) */ - unsigned int syt_offset; + /* set this to zero unless you want a + non-default SYT cycle offset (default = 3 cycles) */ + unsigned int syt_offset; }; /* NOTE: you may only allocate the DV frame ringbuffer once each time @@ -322,32 +322,32 @@ struct dv1394_init { struct dv1394_status { - /* this embedded init struct returns the current dv1394 - parameters in use */ - struct dv1394_init init; - - /* the ringbuffer frame that is currently being - displayed. (-1 if the device is not transmitting anything) */ - int active_frame; - - /* index of the first buffer (ahead of active_frame) that - is ready to be filled with data */ - unsigned int first_clear_frame; - - /* how many buffers, including first_clear_buffer, are - ready to be filled with data */ - unsigned int n_clear_frames; - - /* how many times the DV stream has underflowed, overflowed, - or otherwise encountered an error, since the previous call - to DV1394_GET_STATUS */ - unsigned int dropped_frames; - - /* N.B. The dropped_frames counter is only a lower bound on the actual - number of dropped frames, with the special case that if dropped_frames - is zero, then it is guaranteed that NO frames have been dropped - since the last call to DV1394_GET_STATUS. - */ + /* this embedded init struct returns the current dv1394 + parameters in use */ + struct dv1394_init init; + + /* the ringbuffer frame that is currently being + displayed. (-1 if the device is not transmitting anything) */ + int active_frame; + + /* index of the first buffer (ahead of active_frame) that + is ready to be filled with data */ + unsigned int first_clear_frame; + + /* how many buffers, including first_clear_buffer, are + ready to be filled with data */ + unsigned int n_clear_frames; + + /* how many times the DV stream has underflowed, overflowed, + or otherwise encountered an error, since the previous call + to DV1394_GET_STATUS */ + unsigned int dropped_frames; + + /* N.B. The dropped_frames counter is only a lower bound on the actual + number of dropped frames, with the special case that if dropped_frames + is zero, then it is guaranteed that NO frames have been dropped + since the last call to DV1394_GET_STATUS. + */ }; |