From eaac50f33915dbb5eac906f84bd548c8dab23e33 Mon Sep 17 00:00:00 2001 From: Saxon Date: Sat, 16 Nov 2019 23:12:08 +1030 Subject: [PATCH] codec/mjpeg/jpeg.go: added writeHeader function to write JPEG header This also included the addition of some lunimance and chrominance tables, a multiError type (implements error) and a putter type, that will put uint16s, bytes and "buffers" into a byte slice. --- codec/mjpeg/jpeg.go | 251 ++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 244 insertions(+), 7 deletions(-) diff --git a/codec/mjpeg/jpeg.go b/codec/mjpeg/jpeg.go index 570fa769..be4c7604 100644 --- a/codec/mjpeg/jpeg.go +++ b/codec/mjpeg/jpeg.go @@ -25,19 +25,75 @@ LICENSE package mjpeg import ( + "encoding/binary" "fmt" "io" ) // JPEG marker codes. const ( - soi = 0xd8 // Start of image. - dri = 0xdd // Define restart interval. - dqt = 0xdb // Define quantization tables. - dht = 0xde // Define hierarchical progression. - sos = 0xda // Start of scan. - app0 = 0xe0 // TODO: find out what this is. - sof0 = 0xc0 // Baseline + codeSOI = 0xd8 // Start of image. + codeDRI = 0xdd // Define restart interval. + codeDQT = 0xdb // Define quantization tables. + codeDHT = 0xde // Define hierarchical progression. + codeSOS = 0xda // Start of scan. + codeAPP0 = 0xe0 // TODO: find out what this is. + codeSOF0 = 0xc0 // Baseline +) + +var ( + bitsDCLum = []byte{0, 0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0} + bitsDCChr = []byte{0, 0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0} + bitsACLum = []byte{0, 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 0x7d} + bitsACChr = []byte{0, 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 0x77} + valDC = []byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11} + valACLum = []byte{ + 0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12, + 0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07, + 0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08, + 0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0, + 0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0a, 0x16, + 0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28, + 0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, + 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, + 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, + 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, + 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, + 0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, + 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, + 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, + 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, + 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5, + 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4, + 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2, + 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, + 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, + 0xf9, 0xfa, + } + + valACChr = []byte{ + 0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21, + 0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71, + 0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91, + 0xa1, 0xb1, 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0, + 0x15, 0x62, 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34, + 0xe1, 0x25, 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26, + 0x27, 0x28, 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38, + 0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, + 0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, + 0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, + 0x69, 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, + 0x79, 0x7a, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, + 0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, + 0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, + 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, + 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, + 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, + 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, + 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, + 0xea, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, + 0xf9, 0xfa, + } ) // writeMarker writes an JPEG marker with code to w. @@ -73,3 +129,184 @@ func writeHuffman(w io.Writer, class, id int, bits, values []byte) error { return nil } + +// writeHeader writes a JPEG header to the writer w. +func writeHeader(w io.Writer, size, _type, width, height, nbqTab, dri int, qtable []byte) error { + width <<= 3 + height <<= 3 + + // Indicate start of image. + err := writeMarker(w, codeSOI) + if err != nil { + return fmt.Errorf("could not write SOI marker: %w", err) + } + + err = writeMarker(w, codeAPP0) + if err != nil { + return fmt.Errorf("could not write APP0 marker: %w", err) + } + + // Write JFIF header. + b := make([]byte, 16) + p := putter{} + p.put16(b, 16) + p.putBuf(b, []byte("JFIF"), 5) + p.put16(b, 0x0201) + p.put8(b, 0) + p.put16(b, 1) + p.put16(b, 1) + p.put8(b, 0) + p.put8(b, 0) + _, err = w.Write(b) + if err != nil { + return fmt.Errorf("could not write JFIF header: %w", err) + } + + // If we want to define restart interval. + if dri != 0 { + err = writeMarker(w, codeDRI) + if err != nil { + return fmt.Errorf("could not write DRI marker code: %w", err) + } + + _, err := w.Write([]byte{0x00, 0x04, byte(dri >> 4), byte(dri)}) + if err != nil { + return fmt.Errorf("could not write restart interval value: %w", err) + } + } + + // Define quantization tables. + err = writeMarker(w, codeDQT) + if err != nil { + return fmt.Errorf("could not write DQI marker code: %w", err) + } + + // Calculate table size and create slice for table. + ts := 2 + nbqTab*(1+64) + _, err = w.Write([]byte{byte(ts >> 4), byte(ts)}) + if err != nil { + return fmt.Errorf("could not write quantization table size: %w", err) + } + + for i := 0; i < nbqTab; i++ { + _, err = w.Write([]byte{byte(i)}) + if err != nil { + return fmt.Errorf("could not write quantization table entry no.: %w", err) + } + + _, err = w.Write(qtable[64*i : (64*i)+64]) + if err != nil { + return fmt.Errorf("could not write quantization table entry: %w", err) + } + } + + // Define huffman table. + err = writeMarker(w, codeDHT) + if err != nil { + return fmt.Errorf("could not write DHT marker code: %w", err) + } + + var me multiError + me.add(writeHuffman(w, 0, 0, bitsDCLum, valDC)) + me.add(writeHuffman(w, 0, 1, bitsDCChr, valDC)) + me.add(writeHuffman(w, 1, 0, bitsACLum, valACLum)) + me.add(writeHuffman(w, 1, 1, bitsACChr, valACChr)) + if me != nil { + return fmt.Errorf("error writing huffman tables: %w", err) + } + return nil + + // Start of frame. + err = writeMarker(w, codeSOF0) + if err != nil { + return fmt.Errorf("could not write SOF0 marker code: %w", err) + } + + // Derive sample type. + sample := 1 + if _type != 0 { + sample = 2 + } + + // Derive matrix number. + mtxNo := 0 + if nbqTab == 2 { + mtxNo = 1 + } + + b = make([]byte, 17) + p = putter{} + p.put16(b, 17) + p.put8(b, 8) + p.put16(b, uint16(height)) + p.put16(b, uint16(width)) + p.put8(b, 3) + p.put8(b, 1) + p.put8(b, uint8((2<<4)|sample)) + p.put8(b, 0) + p.put8(b, 2) + p.put8(b, 1<<4|1) + p.put8(b, uint8(mtxNo)) + p.put8(b, 3) + p.put8(b, 1<<4|1) + p.put8(b, uint8(mtxNo)) + _, err = w.Write(b) + if err != nil { + return fmt.Errorf("could not write SOF0 info: %w", err) + } + + // Write start of scan. + err = writeMarker(w, codeSOS) + if err != nil { + return fmt.Errorf("could not write SOS marker code: %w", err) + } + + b = make([]byte, 12) + p = putter{} + p.put16(b, 12) + p.put8(b, 3) + p.put8(b, 1) + p.put8(b, 0) + p.put8(b, 2) + p.put8(b, 17) + p.put8(b, 3) + p.put8(b, 17) + p.put8(b, 0) + p.put8(b, 63) + p.put8(b, 0) + _, err = w.Write(b) + if err != nil { + return fmt.Errorf("could not write SOS info: %w", err) + } + + return nil +} + +type multiError []error + +func (me multiError) Error() string { + return fmt.Sprintf("%v", []error(me)) +} + +func (me multiError) add(e error) { + me = append(me, e) +} + +type putter struct { + idx int +} + +func (p *putter) put16(b []byte, v uint16) { + binary.BigEndian.PutUint16(b[p.idx:], v) + p.idx += 2 +} + +func (p *putter) put8(b []byte, v uint8) { + b[p.idx] = byte(v) + p.idx++ +} + +func (p *putter) putBuf(dst, src []byte, l int) { + copy(dst[p.idx:], src) + p.idx++ +}