Image capture apparatus

An image capture apparatus generates video data from captured images, and generates a video PES (packetized elementary stream) from the video data. The image capture apparatus converts the video PES into a MPEG-2 program stream, and converts the video PES into a MPEG-2 transport stream. The image capture apparatus records the MPEG-2 program stream on a random-access recording medium, and transmits the MPEG-2 transport stream to an external device. The conversion from the video PES into the MPEG-2 program stream and the conversion from the video PES into the MPEG-2 transport stream are performed in parallel thereby enabling the image capture apparatus to perform the recording of the MPEG-2 program stream and the transmission of the MPEG-2 transport stream in parallel.

FIELD OF THE INVENTION

The present invention relates to an image capture apparatus, and more particularly, to an image capture apparatus such as a digital video camera.

BACKGROUND OF THE INVENTION

In addition, for example, as described in Japanese Laid-Open Patent Publication No. 2000-138896, a recording apparatus having the capability to convert MPEG-2TS to MPEG-2PS and record the MPEG-2PS on a disk medium, as well as a recording apparatus having the capability to convert analog video signals and analog audio signals into MPEG-2PS and record the MPEG-2PS on a disk medium, have already been proposed.

Recent digital video cameras are required to have the following five capabilities:

(1) The ability to input and output MPEG-2TS and to record MPEG-2PS to, and to reproduce MPEG-2PS from, a random-access recording medium.

(2) The ability to generate MPEG-2PS and MPEG-2TS from captured images and input audio, and to record MPEG-2PS onto a random-access recording medium and to output MPEG-2TS to an external device.

(3) The ability to generate MPEG-2PS and MPEG-2TS from analog video signals and analog audio signals, and to record MPEG-2PS onto a random-access recording medium and to output MPEG-2TS to an external device.

(4) The ability to convert MPEG-2PS reproduced from a random-access recording medium into MPEG-2TS and output the MPEG-2TS to an external device.

(5) The ability to convert MPEG-2TS input from an external device into MPEG-2PS and record the MPEG-2PS onto a random-access recording medium.

However, no digital video camera having either one of these capabilities has been developed.

SUMMARY OF THE INVENTION

The present invention is conceived in consideration of the above-described conventional art, and has as its object to provide an image capture apparatus having at least one of the above-described capabilities.

According to an aspect of the present invention, there is provided an image capture apparatus comprising: input/output means for inputting and outputting an MPEG transport stream; recording/reproduction means for recording/reproducing an MPEG-2 program stream onto/from a random-access recording medium; and conversion means for converting the MPEG-2 transport stream into the MPEG-2 program stream, and converting the MPEG-2 program stream into the MPEG-2 transport stream.

According to another aspect of the present invention, there is provided an image capture apparatus comprising: program stream generating means for generating MPEG-2 program stream from a captured image and an input audio; transport stream generating means for generating MPEG-2 transport stream from the captured image and the input audio; and output means for outputting the MPEG-2 transport stream to an external device.

According to a further aspect of the present invention, there is provided an image capture apparatus comprising: program stream generating means for generating a MPEG-2 program stream from an analog video signal and an analog audio signal; transport stream generating means for generating a MPEG-2 transport stream from the analog video signal and the analog audio signal; and output means for outputting the MPEG-2 transport stream to an external device.

According to yet further aspect of the present invention, there is provided an image capture apparatus comprising: reproduction means for reproducing an MPEG-2 program stream from a random-access recording medium; conversion means for converting the MPEG-2 program stream into an MPEG-2 transport stream; and output means for outputting the MPEG-2 transport stream to an external device.

According to another aspect of the present invention, there is provided an image capture apparatus comprising: input means for inputting a MPEG-2 transport stream from an external device; conversion means for converting the MPEG-2 transport stream into a MPEG-2 program stream; and recording means for recording the MPEG-2 program stream onto a random-access recording medium.

Other features, objects and advantages of the present invention will be apparent from the following description when taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.

DETAILED DESCRIPTION OF THE INVENTION

Preferred embodiments of the present invention will now be described in detail in accordance with the accompanying drawings. It should be noted that the present embodiment uses PS, TS and PES stipulated by the MPEG-2 Systems.

FIRST EMBODIMENT

In order to facilitate an understanding of the present invention, a description is first given of the main component parts of a digital video camera (DVC)10that is an image capture apparatus according to one embodiment of the present embodiment, with reference toFIG. 1. As can be appreciated by those of ordinary skill in the art, the present invention can also be adapted to image capture apparatuses other than digital video cameras.

A camera unit101, which generates video data from captured images, is comprised of an optical system including a lens, image capturing device and their associated control circuits. A microphone102generates audio data from input audio.

An AV encoder103encodes video data output from the camera unit101or an analog video I/O115as video ES (video Elementary Stream) and converts the video ES to video-use PES (hereinafter “video PES”). The AV encoder103also encodes audio data output from the microphone102or an analog audio I/O116as audio ES (audio Elementary Stream) and converts the audio ES into audio-use PES (hereinafter “audio PES”).

It should be noted that the video encoding scheme used in generating video ES may, for example, be MPEG-2 Video (see ISO/IEC 13818-2: 2000, Information technology—Generic coding of moving pictures and associated audio information: Video). In addition, the audio encoding scheme used in generating audio ES may, for example, be MPEG-2 Audio BC (see ISO/IEC 13818-3: 1998, Information technology—Generic coding of moving pictures and associated audio information—Part 3: Audio), MPEG-2 Audio LSF (see ISO/IEC 13818-3: 1998), or MPEG-2 Audio AAC (see ISO/IEC 13818-7: 1997, Information technology—Generic coding of moving pictures and associated audio information—Part 7: Advanced Audio Coding (AAC)).

A PES/PS converter104converts video PES and audio PES output from the AV encoder103or the PES/TS converter110into MPEG-2PS (MPEG-2 program stream), and also converts the MPEG-2PS output from a recording/reproduction unit105into video PES and audio PES.

The recording/reproduction unit105records MPEG-2PS output from the PES/PS converter104onto a recording medium106, and also reproduces MPEG-2PS designated by a control unit114from the recording medium106. The recording medium106may be a random-access recording medium such as a disk, a semiconductor memory or the like.

An AV decoder107converts video PES output from the AV encoder103or the PES/PS converter104and decodes the video ES into video data. The AV decoder107also converts audio PES output from the AV encoder103or the PES/PS converter104into audio ES, and decodes the audio ES into audio data.

A display unit108displays video data output from the camera unit101or the AV decoder107, and is comprised of a display device such as an LCD, for example. A speaker109outputs audio data output from the microphone102or the AV decoder107.

A PES/TS converter110converts video PES and audio PES output from the AV encoder103or the PES/PS converter104into MPEG-2TS, and converts MPEG-2TS output from a digital communications unit111into video PES and audio PES.

The digital communications unit111outputs MPEG-2TS output from the PES/TS converter110to an external device, and inputs MPEG-2TS from an external device. It should be noted that the digital communications unit111may, for example, conform to IEEE 1394 standard (including IEEE 1394-1995, IEEE 1394a-2000 and extensions thereof) or USB standard (including USB 2.0 standard and extensions thereof).

A memory112stores a play list that the control unit114generates according to user instructions. A play list is a list that specifies how a plurality of MPEG-2PS recorded on the recording medium106are to be reproduced. For example, with a play list it is possible to specify a reproduction sequence or order for a plurality of MPEG-2PS and a reproduction starting point and a reproduction ending point for each of the MPEG-2PS.

An operations panel113sends user instructions to the control unit114and comprises a variety of input devices such as buttons, keys, touch panels and jog dials are used as appropriate. The control unit114controls the functions of the DVC10.

The analog video I/O115converts analog video signals input from an external source into video data, and converts video data output from the camera unit101and the AV decoder106into analog video signals and outputs the analog video signals to an external device.

The analog audio I/O116converts analog audio signals input from an external device into audio data, and converts audio data input from the microphone102or the AV decoder106into analog audio signals and outputs the analog audio signals to an external device.

(1) Camera Mode

Next, a description is given of an example of operations of a DVC10when the DVC10is in a camera mode, with reference to the flow chart inFIG. 2.

In a step S201, when a user uses the operations panel113to turn the camera mode on, the control unit114reports the start of the camera mode to the components. In response to such notification, the components start predetermined operations. In other words, the camera unit101starts to generate video data from captured images and the microphone102starts to generate audio data from input audio. The display unit108starts to display video data output from the camera unit101. The speaker109starts to output audio data output from the microphone102. The analog video I/O115starts to convert video data output from the camera unit101into analog video signals and outputs the analog video signals to an external device. The analog audio I/O116starts to convert audio data output from the microphone102into analog audio signals and outputs the analog audio signals to an external device.

In a step S202, the AV encoder103starts to encode video data output from the camera unit101as video ES and convert the video ES into video PES. At the same time, the AV encoder103starts to encode audio data output from the microphone102as audio ES and convert the audio ES into audio PES.

In a step S203, the PES/PS converter104starts to convert the video PES and the audio PES output from the AV encoder103into MPEG-2PS. At the same time, the PES/TS converter110starts to convert the video PES and the audio PES output from the AV encoder103into MPEG-2TS. That is, the DVC10can simultaneously generate MPEG-2PS and MPEG-2TS from the captured images and the input audio. The digital communications unit111starts to output MPEG-2TS output from the PES/TS converter110to an external device. The recording/reproduction unit105waits to record MPEG-2PS onto the recording medium106until there is an instruction to start recording.

In a step S204, the control unit114determines whether or not an instruction to start recording has been issued by determining, for example, whether or not a REC button (that is, a recording start/stop button) on the operations panel113has been pressed. Processing proceeds to a step S205if it is detected that the REC button has been pressed.

In a step S205, the control unit114sends an instruction to start recording to the recording/reproduction unit105. The recording/reproduction unit105starts to record the MPEG-2PS output from the PES/PS converter104to the recording medium106.

Thus, a DVC10according to this embodiment can generate MPEG-2TS and MPEG-2PS from the captured image and the input audio, and output the generated MPEG-2TS to an external device and output the generated MPEG-2PS to the recording medium106.

In addition, the DVC10according to this embodiment can simultaneously generate MPEG-2PS from captured images and input audio and MPEG-2TS from captured images and input audio.

(2) Digital Output Mode

Next, a description is given of the operations of the DVC10when the DVC10is in a digital output mode, with reference to the flow chart ofFIG. 3.

In a step S301, when a user uses the operations panel113to turn the digital output mode on, the control unit114reports the start of the digital output mode to the components. The control unit114selects the MPEG-2PS to be reproduced in accordance with a user instruction or a play list, and notifies the selected MPEG-2PS to the recording/reproduction unit105. The recording/reproduction unit105reproduces the MPEG-2PS designated by the control unit114at normal speed from the recording medium106. The PES/PS converter104converts the MPEG-2PS output from the recording/reproduction unit105into video PES and audio PES. The AV decoder106converts video PES output from the PES/PS converter104to video ES and starts to decode the video ES into video data, and at the same time converts the audio PES output from the PES/PS converter104into audio ES and starts decoding the audio ES into audio data. The display unit108starts to display video data output from the AV decoder106. The speaker109starts to output audio data output from the AV decoder106. The analog video I/O115starts to convert video data output from the AV decoder106into analog video signals and output the analog video signals to an external device. The analog audio I/O116starts to convert audio data output from the AV decoder106into analog audio signals and output the analog audio signals to an external device.

In a step S302, the control unit114determines whether or not to prohibit TS conversion (that is, converting MPEG-2PS into MPEG-2TS). In this embodiment, TS conversion of MEPG-2PS is prohibited when attribute information prohibiting the TS conversion is attached to the MPEG-2PS output from the recording/reproduction unit105. If TS conversion is prohibited, then processing proceeds to a step S303. If TS conversion is not prohibited, then processing proceeds to a step S304.

In step S303the control unit114prohibits TS conversion. In such a case, the DVC10outputs a null packet (that is, a packet without a payload, or a packet of which payload contains invalid data) from the digital communications unit111.

In step S304, the control unit114permits TS conversion.

In a step S305, the control unit114determines whether or not to execute encryption (that is, to encrypt MPEG-2TS) and sends the results of that determination to the PES/TS converter110. In this embodiment, the control unit114determines to execute encryption if attribute information that requests encryption is attached to the MPEG-2PS output from the recording/reproduction unit105. If encryption is to be executed, then processing proceeds to a step S306. If encryption is not to be executed, then processing proceeds to a step S307.

In step S306, the PES/TS converter110starts to convert video PES and audio PES output from the PES/PS converter104into MPEG-2TS, and at the same time starts to encrypt the MPEG-2TS payload. The digital communications unit111starts to output the MPEG-2TS encrypted by the PES/TS converter110to an external device.

In step S307, the PES/TS converter110starts to convert the video PES and the audio PES output from the PES/PS converter104into MPEG-2TS. Here, the MPEG-2TS payload is not encrypted. The digital communications unit111starts to output the MPEG-2TS output from the PES/TS converter110to an external device.

In a step S308, the control unit114determines whether or not there is an MPEG-2PS to be reproduced next. If the user specifies an MPEG-2PS to be reproduced next, or if there is still MPEG-2PS to be reproduced on the play list, then the control unit114determines that there is MPEG-2PS to be reproduced next, in which case the process returns to step S301.

Thus, the DVC10according to the present embodiment can convert MPEG-2PS reproduced from the recording medium106into MPEG-2TS according to a user instruction or a play list and output the MPEG-2TS to an external device.

In addition, the DVC10according to this embodiment, when TS conversion of the MPEG-2PS reproduced from the recording medium106is prohibited, thus the conversion of that MPEG-2PS into MPEG-2TS can be prohibited. In this case, the DVC10can output a null packet (that is, a packet without a payload or a packet of which payload contains invalid data) from the digital communications unit111.

In addition, the DVC10according to the embodiment described above can encrypt and output MPEG-2TS.

It should be noted that the DVC10according to this embodiment can reproduce the MPEG-2PS fast or slow. In this case, the PES/TS converter110may convert video PES, obtained either at intervals or repeatedly, into MPEG-2TS, or, alternatively, I pictures may be extracted from the MPEG-2PS obtained either at intervals or repeatedly and MPEG-2TS may be generated from the extracted I pictures.

(3) Digital Input Mode

Next, a description is given of the operation of the DVC10when the DVC10is in a digital input mode, with reference to the flow chart ofFIG. 4.

In a step S401, when the user uses the operations panel113to turn the digital input mode on, the control unit114reports the start of the digital input mode to the component parts. The digital communications unit111starts to input the MPEG-2TS selected by the user from an external device.

In a step S402, the PES/TS converter110starts to convert the MPEG-2TS output from the digital communications unit111into video PES and audio PES. The AV decoder107starts to convert the video PES output from the PES/TS converter110into video ES and decode that video ES into video data. In addition, the AV decoder107also starts to convert the audio PES output from the PES/TS converter110into audio ES and decode that audio ES into audio data. The display unit108starts to display the video data output from the AV decoder107. The speaker109starts to output audio data output from the AV decoder107. The analog video I/O115starts to convert video data output from the AV decoder107into analog video signals and output those analog video signals to an external unit. The analog audio I/O116starts to convert audio data output from the AV decoder107into analog audio signals and output those analog audio signals to an external device.

In a step S403, the control unit114determines whether or not it is necessary to change at least one of either the number of pixels (also called the resolution), the frame rate (that is, the number of frames per second), the compression rate, the sampling frequency or the audio coding method. In the present embodiment, if the user inputs to the DVC10an instruction to change at least one of a preset number of pixels, frame rate, compression rate, sampling frequency or audio coding method, the control unit114determines that a change is necessary and reports the content of the change to the AV decoder107. If change is necessary, then processing proceeds to a step S404. If no change is necessary, then processing proceeds to a step S406.

In step S404, if it is necessary to change at least one of either the number of pixels, the frame rate or the compression rate, the AV decoder107starts to change at least one of the number of pixels, frame rate or compression rate of the video data in response to notification from the control unit114. On the other hand, if it is necessary to change at least one of either the sampling frequency or the audio coding method, the AV decoder107starts to change at least one of the sampling frequency or the audio coding method. The AV encoder103starts to encode video data output form the AV decoder107to video ES and in turn the video ES to video PES. The AV encoder103also starts to encode audio data output from the AV decoder107to audio ES and in turn the audio ES to audio PES.

In a step S405, the PES/PS converter104starts to convert video PES and audio PES output from the AV encoder103into MPEG-2PS.

In step S406, the PES/ES converter104starts to convert video PES and audio PES output from the PES/TS converter110into MPEG-2PS.

In a step S407, the control unit114determines whether or not an instruction to start recording has been issued, for example, by determining whether or not the REC button has been pressed. If the control unit114detects that the REC button has been pressed, then processing proceeds to a step S408.

In step S408, the control unit114sends the instruction to start recording to the recording/reproduction unit105. The recording/reproduction unit105starts to record the MPEG-2PS output from the PES/PS converter104onto the recording medium106.

As described above, the DVC10according to the present embodiment can convert MPEG-2TS input from an external device into MPEG-2PS and records the MPEG-2PS on a recording medium106.

In addition, the DVC10according to the present embodiment can change the number of pixels, frame rate and compression rate of the video data obtained from the MPEG-2TS when converting MPEG-2TS into MPEG-2PS and recording the MPEG-2PS onto the recording medium106. For example, the DVC10can change the number of pixels from 1920×1080 pixels to 720×480 pixels, and can change the frame rate from 60 Hz (60 frames/second) to 30 Hz (30 frames/second).

In addition, the DVC10according to the present embodiment can change the audio data sampling frequency and audio coding mode of the audio data obtained from the MPEG-2TS when converting the MPEG-2TS into MPEG-2PS, and recording the MPEG-2PS onto the recording medium106. For example, the DVC10can change the sampling frequency from 48 kHz to 32 kHz, and can change the audio coding method from MPEG-2 Audio BC to MPEG-2 Audio AAC.

(4) Analog Input Mode

Next, a description is given of the operation of a DVC10when the DVC10is in an analog input mode, with reference to the flow chart ofFIG. 5.

In a step S501, when a user uses the operations panel113to turn the analog input mode on, the control unit114reports the start of the analog input mode to the components. The analog video I/O115starts to convert the analog video signals input from an external device into video data and output the video data to the AV encoder103and the display unit108. The analog audio I/O116starts to convert the analog audio signals input from an external device into audio data and output the audio data to the AV encoder103and the speaker109. The display unit108starts to display the video data output from the analog video I/O115. The speaker109starts to output the audio data output from the analog audio I/O116.

In a step S502, the AV encoder103starts to encode the video data output from the analog video I/O115as video ES and converts the video ES into video PES. At the same time, the AV encoder103starts to encode the audio data output from the analog audio I/O116as audio ES and convert that audio ES into audio PES.

In a step S503, the PES/PS converter104starts to convert the video PES and audio PES output from the AV encoder103into MPEG-2PS. On the other hand, the PES/TS converter110starts to convert the video PES and audio PES output from the AV encoder103into MPEG-2TS. That is, the DVC10can simultaneously generate MPEG-2PS as well as MPEG-2TS from the analog video signals and analog audio signals. The digital communications unit111starts to output MPEG-2TS output from the PES/TS converter110to an external device. The recording/reproduction unit105waits for an instruction to start recording to record the MPEG-2PS onto the recording medium106.

In a step S504, the control unit114determines whether or not an instruction to start recording has been issued, for example by determining whether or not the REC button has been pressed. If the control unit114detects that the REC button has been pressed, then processing proceeds to a step S505.

In step S505, the control unit114reports the instruction to start recording to the recording/reproduction unit105. The recording/reproduction unit105then starts to record the MPEG-2PS output from the PES/PS converter104onto the recording medium106.

As described above, the DVC10according to the present embodiment can generate MPEG-2TS and MPEG-2PS from analog video signals and analog audio signals, and can output the generated MPEG-2TS to an external device and can record the generated MPEG-2PS to the recording medium106.

In addition, the DVC10according to the present embodiment can simultaneously generate MPEG-2PS as well as MPEG-2TS from analog video signals and analog audio signals.

OTHER EMBODIMENTS

As can be appreciated by those of ordinary skill in the art, the present invention is not limited to the embodiment described above but can be adapted to other embodiments as well.

Thus, for example, the present invention may be adapted to an embodiment that combines a menu screen, warning mark or other image data with the video data prior to converting the video data output from the camera unit101or the AV decoder107into MPEG-2TS and outputting the MPEG-2TS to an external device.

According to the image capture apparatus of the above embodiments, it is possible to input and output MPEG-2TS, and record and reproduce MPEG-2PS.

In addition, according to the image capture apparatus of the above embodiments, it is possible to generate MPEG-2 program stream (PS) and MPEG-2 transport stream (TS) from captured images and input audio.

In addition, according to the image capture apparatus of the above embodiments, it is possible to generate MPEG-2 program stream and MPEG-2 transport stream from analog video signals and analog audio signals.

In addition, according to the image capture apparatus of the above embodiments, it is possible to convert an MPEG-2 program stream reproduced from a random-access recording medium into an MPEG-2 transport stream and output the MPEG-2 transport stream to an external device.

In addition, according to the image capture apparatus of the above embodiments, it is possible to convert an MPEG-2 transport stream input from an external device into an MPEG-2 program stream and record the MPEG-2 program stream onto a random-access recording medium106.