CN103747253B - A kind of video data encoder transmission method based on FIFO - Google Patents

Abstract

The invention discloses a kind of video data encoder transmission method based on FIFO, including step：S1. Initialize installation is carried out to the multiple parameters of fifo buffer；S2. video data encoder is write in a dynamic fashion by fifo buffer according to the parameter for arranging, the dynamical fashion represents to write save as in unit variable-length state, for the frame of video of correspondence storage write, the operation of the internal memory variable-length state representation internal memory is how under absorbed with the video frame size of write according to each r/w cell；S3. the video data encoder of write fifo buffer is read.The present invention has the characteristics of real-time is high, reliability is high and low in resources consumption.

Description

A kind of video data encoder transmission method based on FIFO

Technical field

The present invention relates to a kind of buffered technology of the video data encoder of web camera, more particularly to one kind is based on The video data encoder transmission method of FIFO.

Background technology

The video data encoder transmission technology of the web camera of main flow mainly has two kinds now, and one is wait more than single task Sequence buffer technology, as shown in figure 1, mean web camera be notified that after often encoding out a frame data network send mould Block, then the coding module of web camera enter waiting state, until network sending module has sent a just frame data Carry out coding next time afterwards again.Two is the sequence buffer technology of multitask multicopy, as shown in Fig. 2 meaning that network is taken the photograph Camera is few greatly in the internal memory of the multiple fixations of coding module default allocation, has compiled a frame data every time and has just copied data to acquiescence In the fixed memory for distributing.Network sending module again fixed memory copy out coding after a frame data for sending.

But the poor real of the sequence buffer technology waited one single task of prior art more.Two multitask of prior art is more The sequence buffer technical disadvantages resource consumption of copy is big, design is complicated, reliability is low, very flexible.

The content of the invention

In order to overcome the deficiencies in the prior art, the invention provides a kind of video data encoder transmission side based on FIFO Method, the problems such as it can solve big poor real, resource consumption, low reliability and very flexible.

The technical solution used in the present invention is as follows：

A kind of video data encoder transmission method based on FIFO, including step：

S1. Initialize installation is carried out to the multiple parameters of fifo buffer；

S2. video data encoder is write in a dynamic fashion by fifo buffer, the dynamical fashion according to the parameter for arranging Represent in r/w cell and save as variable-length state, for the frame of video of correspondence storage write, the internal memory variable-length state table Show internal memory operation be according to each r/w cell with write video frame size distribution；

S3. the video data encoder of write fifo buffer is read.

Wherein, the parameter includes:FIFO start address, FIFO total lengths, r/w cell, reading cell array and write-once Greatest length；Wherein write-once greatest length represents the protection zone of fifo buffer.

The present invention is appreciated that：FIFO allows multiple users to read, but the parameter initialization in fifo buffer is arranged When have determined that the number of users of maximum reads the array size of unit, and it is exactly the reading r/w cell one by one to read unit Go out, one is read the client that unit represents a request video flowing of network sending module.

The r/w cell internal memory of the present invention storage video data encoder mentioned for step S2 is variable, this is because often The video frame size that the individual time period transmits all may be different, and in order to not waste memory headroom, the operation of internal memory is to write Unit is border, how under absorbed with the video frame size of write according to each r/w cell.

Can be well understood by, general operation system is all to carry out by byte to memory address.Namely 0 He of memory address Memory address 1 can deposit the data of 2 bytes.For example, the data of 4 bytes are written with the position of memory address 0, then Read the data for just having write to be accomplished by from address 0 starting to read address 3 terminating.From the example above it is envisioned that into The position of memory address 0 writes one new " r/w cell ".Assume information 3 bytes behind 1 byte of " r/w cell " It is video requency frame data, then the beginning border of this " r/w cell " is memory address 0, and end boundary is memory address 3, these letters Breath is also stored in inside the information of " r/w cell " of 1 byte.

Again " r/w cell " that size is 10 bytes can be write from the position of memory address 4 in the same manner, due to will " r/w cell " size of write is 10 bytes, therefore the beginning border of this r/w cell is memory address 4, and end boundary is interior Deposit address 13.

Because " r/w cell " is with border, " r/w cell " can be pressed according to border when " r/w cell " is read Different length and memory address is continuously to read out.

The write of the video data encoder specifically video encoding module often completes one-frame video data and encodes then it A r/w cell toward fifo buffer writes, and then next frame coding completes to write next r/w cell again, carries out down according to this Go.

The write-once process includes the operation of data Overflow handling, specific as follows：

Write starts, and judges whether video data encoder has been written into protection zone mark, if it is, new r/w cell First r/w cell of fifo buffer covered, is changed to no whether data have been written into protection zone mark, is then terminated The write-once of fifo buffer；If it is not, then new r/w cell is directly appended to last r/w cell of fifo buffer Below, then terminate the write-once of fifo buffer.

The present invention compares other prior arts and increased a data Overflow handling operation, and FIFO total lengths are that initialization sets Determination is put, when constantly there is r/w cell to write with video requency frame data, internal memory constantly can be allocated away, when occurring new writing list Unit can carry out Overflow handling to the data into protection zone when entering protection zone, and the data to protection zone can move relief area Most start, that is, cover earliest data, and as video data requires real-time, so the data of write are general soon Can be sent on network, capped earliest data do not interfere with whole transmitting procedure.

When occur new r/w cell cover fifo buffer write at first r/w cell when, next new r/w cell Write is added to behind the r/w cell after covering.

Specifically on the basis of fixed reading cell array, each reads unit to data in r/w cell to step S3 Read.That is, the readings cell array for determining represent the client for asking video flowing that determines how many, then each client End receives multiple r/w cell data by network sending module, namely one enters to have more.

The readout is specific as follows：

S11：Reading starts, and whether there is available reading unit in searching the reading cell array of fifo buffer, if Then distribute a reading unit, if otherwise terminating to read；

S12：Whether there is effective r/w cell in searching the r/w cell of fifo buffer, if it is, buffering from FIFO The r/w cell of the write earliest for current reading unit is found out in effective r/w cell in area；If it is not, then waiting for a period of time；

S13：A frame video data encoder of r/w cell is returned to network sending module simultaneously repeat step S12.

Wherein the expression of step S13 is then conveyed it to by reading the video data encoder in unit reading r/w cell Network sending module then proceedes to repeat step S12.With reference to step S3, after video data encoder is received, network sends mould Block will send it to the client for asking video.

The present invention is had the advantage that compared with prior art：

1. real-time is high.Write and read is all had very high independence in different threads in the present invention, is not deposited In the mechanism for waiting write-read, therefore real-time is higher；

2. reliability is high.There is the Overflow handling of data in the present invention, it is hereby ensured the reliability of the design；

3. low in resources consumption.As the data transfer in middle motion is carried out in the good internal memory of predistribution, do not have Unnecessary memory copying process.

Description of the drawings

The fundamental diagram of Fig. 1 prior arts one；

The fundamental diagram of Fig. 2 prior arts two；

Fig. 3 FIFO initialization flowcharts of the present invention；

The content logic structure chart of Fig. 4 FIFO of the present invention；

Fig. 5 ablation process flow charts of the present invention；

Fig. 6 readout flow charts of the present invention.

Specific embodiment

The invention will be further described below in conjunction with the accompanying drawings.

As shown in figure 3, carrying out Initialize installation to five parameters of FIFO namely fifo buffer, the parameter is specifically wrapped Include:FIFO start address, FIFO total lengths, r/w cell, reading cell array and write-once greatest length.

As shown in figure 4, from the figure, it can be seen that each read unit the data in r/w cell are read out, wherein once Write greatest length belongs to the protection zone of fifo buffer.

As shown in figure 5, video encoding module often complete one-frame video data encode toward fifo buffer write, it is described once Ablation process is specific as follows：

Write starts, and judges whether video data encoder has been written into protection zone mark, if it is, new r/w cell Cover the r/w cell for writing at first of fifo buffer, data whether have been written into protection zone mark be changed to it is no, then Terminate the write-once of fifo buffer；If it is not, then new r/w cell is directly appended to last of fifo buffer writing Behind unit, then terminate the write-once of fifo buffer.

In addition, when occur new r/w cell cover fifo buffer write at first r/w cell when, it is next new R/w cell write is added to behind it.

As shown in fig. 6, when the client of request video flowing is read in r/w cell to FIFO requests by network sending module Video data encoder, the readout are specific as follows：

S11：Reading starts, and whether there is available reading unit in searching the reading cell array of fifo buffer, if Then distribute a reading unit, if otherwise terminating to read；

S12：Whether there is effective r/w cell in searching the r/w cell of fifo buffer, if it is, buffering from FIFO The r/w cell of the write earliest for current reading unit is found out in effective r/w cell in area；If it is not, then waiting for a period of time；

S13：A frame video data encoder of r/w cell is returned to network sending module simultaneously repeat step S12.

Claims (5)

1. a kind of video data encoder transmission method based on FIFO, it is characterised in that including step：

S1. Initialize installation is carried out to the multiple parameters of fifo buffer, the parameter includes：FIFO start address, FIFO are total Length, r/w cell, reading cell array and write-once greatest length；Wherein write-once greatest length belongs to fifo buffer Protection zone；

S2. video data encoder is write in a dynamic fashion by fifo buffer according to the parameter for arranging, the dynamical fashion is represented Variable-length state is saved as in r/w cell, for the frame of video of correspondence storage write, in the internal memory variable-length state representation The operation deposited is the video frame size distribution according to each r/w cell with write；

S3. the video data encoder of write fifo buffer is read；

Wherein, the write-once process includes the operation of data Overflow handling, specific as follows：

Write starts, and judges whether video data encoder has been written into protection zone mark, if it is, new r/w cell is covered To the r/w cell for writing at first of fifo buffer, be changed to no whether data have been written into protection zone mark, then terminate The write-once of fifo buffer；If it is not, then new r/w cell is directly appended to last r/w cell of fifo buffer Below, then terminate the write-once of fifo buffer.

2. a kind of video data encoder transmission method based on FIFO according to claim 1, it is characterised in that described to regard The write specifically video encoding module of frequency coded data often completes one-frame video data and encodes then it toward fifo buffer One r/w cell writes, and then next frame coding completes to write next r/w cell again, goes on according to this.

3. a kind of video data encoder transmission method based on FIFO according to claim 1, it is characterised in that work as appearance New r/w cell cover fifo buffer write at first r/w cell when, next new r/w cell write is added to cover Behind r/w cell after lid.

4. a kind of video data encoder transmission method based on FIFO according to claim 1, it is characterised in that the step Specifically on the basis of fixed reading cell array, each reads reading of the unit to data in r/w cell to rapid S3.

5. a kind of video data encoder transmission method based on FIFO according to claim 4, it is characterised in that the reading Go out process specific as follows：

S11：Reading starts, and whether there is available reading unit in searching the reading cell array of fifo buffer, if it is, point With a reading unit, if it is not, then terminating to read；

S12：Whether there is effective r/w cell in searching the r/w cell of fifo buffer, if it is, from fifo buffer The r/w cell of to current reading unit for earliest write is found out in r/w cell effectively；If it is not, then waiting for a period of time；

S13：A frame video data encoder of r/w cell is returned to network sending module simultaneously repeat step S12.