20f325f320
Everything written with this bitstream writer is 8/16 bit units (except for a pair of 4 bit values), so using a bitstream writer isn't necessary. Signed-off-by: Martin Storsjö <martin@martin.st>
376 lines
12 KiB
C
376 lines
12 KiB
C
/*
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* RTP JPEG-compressed Video Depacketizer, RFC 2435
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* Copyright (c) 2012 Samuel Pitoiset
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*
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* This file is part of Libav.
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*
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* Libav is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* Libav is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with Libav; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "avformat.h"
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#include "rtpdec_formats.h"
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#include "libavutil/intreadwrite.h"
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#include "libavcodec/mjpeg.h"
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#include "libavcodec/bytestream.h"
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/**
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* RTP/JPEG specific private data.
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*/
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struct PayloadContext {
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AVIOContext *frame; ///< current frame buffer
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uint32_t timestamp; ///< current frame timestamp
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int hdr_size; ///< size of the current frame header
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};
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static const uint8_t default_quantizers[128] = {
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/* luma table */
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16, 11, 12, 14, 12, 10, 16, 14,
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13, 14, 18, 17, 16, 19, 24, 40,
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26, 24, 22, 22, 24, 49, 35, 37,
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29, 40, 58, 51, 61, 60, 57, 51,
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56, 55, 64, 72, 92, 78, 64, 68,
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87, 69, 55, 56, 80, 109, 81, 87,
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95, 98, 103, 104, 103, 62, 77, 113,
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121, 112, 100, 120, 92, 101, 103, 99,
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/* chroma table */
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17, 18, 18, 24, 21, 24, 47, 26,
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26, 47, 99, 66, 56, 66, 99, 99,
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99, 99, 99, 99, 99, 99, 99, 99,
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99, 99, 99, 99, 99, 99, 99, 99,
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99, 99, 99, 99, 99, 99, 99, 99,
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99, 99, 99, 99, 99, 99, 99, 99,
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99, 99, 99, 99, 99, 99, 99, 99,
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99, 99, 99, 99, 99, 99, 99, 99
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};
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static PayloadContext *jpeg_new_context(void)
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{
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return av_mallocz(sizeof(PayloadContext));
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}
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static inline void free_frame_if_needed(PayloadContext *jpeg)
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{
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if (jpeg->frame) {
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uint8_t *p;
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avio_close_dyn_buf(jpeg->frame, &p);
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av_free(p);
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jpeg->frame = NULL;
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}
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}
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static void jpeg_free_context(PayloadContext *jpeg)
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{
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free_frame_if_needed(jpeg);
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av_free(jpeg);
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}
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static int jpeg_create_huffman_table(PutByteContext *p, int table_class,
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int table_id, const uint8_t *bits_table,
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const uint8_t *value_table)
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{
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int i, n = 0;
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bytestream2_put_byte(p, table_class << 4 | table_id);
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for (i = 1; i <= 16; i++) {
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n += bits_table[i];
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bytestream2_put_byte(p, bits_table[i]);
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}
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for (i = 0; i < n; i++) {
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bytestream2_put_byte(p, value_table[i]);
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}
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return n + 17;
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}
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static void jpeg_put_marker(PutByteContext *pbc, int code)
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{
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bytestream2_put_byte(pbc, 0xff);
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bytestream2_put_byte(pbc, code);
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}
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static int jpeg_create_header(uint8_t *buf, int size, uint32_t type, uint32_t w,
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uint32_t h, const uint8_t *qtable, int nb_qtable)
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{
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PutByteContext pbc;
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uint8_t *dht_size_ptr;
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int dht_size, i;
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bytestream2_init_writer(&pbc, buf, size);
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/* Convert from blocks to pixels. */
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w <<= 3;
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h <<= 3;
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/* SOI */
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jpeg_put_marker(&pbc, SOI);
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/* JFIF header */
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jpeg_put_marker(&pbc, APP0);
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bytestream2_put_be16(&pbc, 16);
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bytestream2_put_buffer(&pbc, "JFIF", 5);
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bytestream2_put_be16(&pbc, 0x0201);
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bytestream2_put_byte(&pbc, 0);
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bytestream2_put_be16(&pbc, 1);
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bytestream2_put_be16(&pbc, 1);
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bytestream2_put_byte(&pbc, 0);
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bytestream2_put_byte(&pbc, 0);
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/* DQT */
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jpeg_put_marker(&pbc, DQT);
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bytestream2_put_be16(&pbc, 2 + nb_qtable * (1 + 64));
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for (i = 0; i < nb_qtable; i++) {
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bytestream2_put_byte(&pbc, i);
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/* Each table is an array of 64 values given in zig-zag
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* order, identical to the format used in a JFIF DQT
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* marker segment. */
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bytestream2_put_buffer(&pbc, qtable + 64 * i, 64);
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}
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/* DHT */
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jpeg_put_marker(&pbc, DHT);
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dht_size_ptr = pbc.buffer;
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bytestream2_put_be16(&pbc, 0);
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dht_size = 2;
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dht_size += jpeg_create_huffman_table(&pbc, 0, 0,avpriv_mjpeg_bits_dc_luminance,
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avpriv_mjpeg_val_dc);
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dht_size += jpeg_create_huffman_table(&pbc, 0, 1, avpriv_mjpeg_bits_dc_chrominance,
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avpriv_mjpeg_val_dc);
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dht_size += jpeg_create_huffman_table(&pbc, 1, 0, avpriv_mjpeg_bits_ac_luminance,
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avpriv_mjpeg_val_ac_luminance);
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dht_size += jpeg_create_huffman_table(&pbc, 1, 1, avpriv_mjpeg_bits_ac_chrominance,
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avpriv_mjpeg_val_ac_chrominance);
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AV_WB16(dht_size_ptr, dht_size);
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/* SOF0 */
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jpeg_put_marker(&pbc, SOF0);
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bytestream2_put_be16(&pbc, 17);
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bytestream2_put_byte(&pbc, 8);
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bytestream2_put_be16(&pbc, h);
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bytestream2_put_be16(&pbc, w);
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bytestream2_put_byte(&pbc, 3);
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bytestream2_put_byte(&pbc, 1);
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bytestream2_put_byte(&pbc, type ? 34 : 33);
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bytestream2_put_byte(&pbc, 0);
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bytestream2_put_byte(&pbc, 2);
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bytestream2_put_byte(&pbc, 17);
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bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0);
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bytestream2_put_byte(&pbc, 3);
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bytestream2_put_byte(&pbc, 17);
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bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0);
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/* SOS */
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jpeg_put_marker(&pbc, SOS);
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bytestream2_put_be16(&pbc, 12);
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bytestream2_put_byte(&pbc, 3);
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bytestream2_put_byte(&pbc, 1);
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bytestream2_put_byte(&pbc, 0);
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bytestream2_put_byte(&pbc, 2);
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bytestream2_put_byte(&pbc, 17);
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bytestream2_put_byte(&pbc, 3);
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bytestream2_put_byte(&pbc, 17);
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bytestream2_put_byte(&pbc, 0);
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bytestream2_put_byte(&pbc, 63);
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bytestream2_put_byte(&pbc, 0);
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/* Return the length in bytes of the JPEG header. */
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return bytestream2_tell_p(&pbc);
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}
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static void create_default_qtables(uint8_t *qtables, uint8_t q)
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{
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int factor = q;
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int i;
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factor = av_clip(q, 1, 99);
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if (q < 50)
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q = 5000 / factor;
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else
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q = 200 - factor * 2;
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for (i = 0; i < 128; i++) {
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int val = (default_quantizers[i] * q + 50) / 100;
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/* Limit the quantizers to 1 <= q <= 255. */
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val = av_clip(val, 1, 255);
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qtables[i] = val;
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}
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}
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static int jpeg_parse_packet(AVFormatContext *ctx, PayloadContext *jpeg,
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AVStream *st, AVPacket *pkt, uint32_t *timestamp,
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const uint8_t *buf, int len, int flags)
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{
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uint8_t type, q, width, height;
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const uint8_t *qtables = NULL;
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uint16_t qtable_len;
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uint32_t off;
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int ret;
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if (len < 8) {
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av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
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return AVERROR_INVALIDDATA;
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}
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/* Parse the main JPEG header. */
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off = AV_RB24(buf + 1); /* fragment byte offset */
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type = AV_RB8(buf + 4); /* id of jpeg decoder params */
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q = AV_RB8(buf + 5); /* quantization factor (or table id) */
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width = AV_RB8(buf + 6); /* frame width in 8 pixel blocks */
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height = AV_RB8(buf + 7); /* frame height in 8 pixel blocks */
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buf += 8;
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len -= 8;
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/* Parse the restart marker header. */
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if (type > 63) {
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av_log(ctx, AV_LOG_ERROR,
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"Unimplemented RTP/JPEG restart marker header.\n");
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return AVERROR_PATCHWELCOME;
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}
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/* Parse the quantization table header. */
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if (off == 0) {
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/* Start of JPEG data packet. */
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uint8_t new_qtables[128];
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uint8_t hdr[1024];
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if (q > 127) {
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uint8_t precision;
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if (len < 4) {
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av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
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return AVERROR_INVALIDDATA;
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}
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/* The first byte is reserved for future use. */
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precision = AV_RB8(buf + 1); /* size of coefficients */
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qtable_len = AV_RB16(buf + 2); /* length in bytes */
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buf += 4;
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len -= 4;
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if (precision)
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av_log(ctx, AV_LOG_WARNING, "Only 8-bit precision is supported.\n");
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if (q == 255 && qtable_len == 0) {
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av_log(ctx, AV_LOG_ERROR,
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"Invalid RTP/JPEG packet. Quantization tables not found.\n");
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return AVERROR_INVALIDDATA;
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}
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if (qtable_len > 0) {
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if (len < qtable_len) {
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av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
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return AVERROR_INVALIDDATA;
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}
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qtables = buf;
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buf += qtable_len;
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len -= qtable_len;
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}
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}
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/* Skip the current frame in case of the end packet
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* has been lost somewhere. */
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free_frame_if_needed(jpeg);
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if ((ret = avio_open_dyn_buf(&jpeg->frame)) < 0)
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return ret;
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jpeg->timestamp = *timestamp;
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if (!qtables) {
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create_default_qtables(new_qtables, q);
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qtables = new_qtables;
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qtable_len = sizeof(new_qtables);
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}
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/* Generate a frame and scan headers that can be prepended to the
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* RTP/JPEG data payload to produce a JPEG compressed image in
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* interchange format. */
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jpeg->hdr_size = jpeg_create_header(hdr, sizeof(hdr), type, width,
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height, qtables,
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qtable_len > 64 ? 2 : 1);
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/* Copy JPEG header to frame buffer. */
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avio_write(jpeg->frame, hdr, jpeg->hdr_size);
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}
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if (!jpeg->frame) {
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av_log(ctx, AV_LOG_ERROR,
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"Received packet without a start chunk; dropping frame.\n");
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return AVERROR(EAGAIN);
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}
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if (jpeg->timestamp != *timestamp) {
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/* Skip the current frame if timestamp is incorrect.
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* A start packet has been lost somewhere. */
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free_frame_if_needed(jpeg);
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av_log(ctx, AV_LOG_ERROR, "RTP timestamps don't match.\n");
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return AVERROR_INVALIDDATA;
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}
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if (off != avio_tell(jpeg->frame) - jpeg->hdr_size) {
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av_log(ctx, AV_LOG_ERROR,
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"Missing packets; dropping frame.\n");
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return AVERROR(EAGAIN);
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}
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/* Copy data to frame buffer. */
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avio_write(jpeg->frame, buf, len);
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if (flags & RTP_FLAG_MARKER) {
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/* End of JPEG data packet. */
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PutBitContext pbc;
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uint8_t buf[2];
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/* Put EOI marker. */
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init_put_bits(&pbc, buf, sizeof(buf));
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put_marker(&pbc, EOI);
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flush_put_bits(&pbc);
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avio_write(jpeg->frame, buf, sizeof(buf));
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/* Prepare the JPEG packet. */
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av_init_packet(pkt);
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pkt->size = avio_close_dyn_buf(jpeg->frame, &pkt->data);
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if (pkt->size < 0) {
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av_log(ctx, AV_LOG_ERROR,
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"Error occured when getting frame buffer.\n");
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jpeg->frame = NULL;
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return pkt->size;
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}
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pkt->stream_index = st->index;
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pkt->destruct = av_destruct_packet;
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/* Re-init the frame buffer. */
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jpeg->frame = NULL;
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return 0;
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}
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return AVERROR(EAGAIN);
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}
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RTPDynamicProtocolHandler ff_jpeg_dynamic_handler = {
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.enc_name = "JPEG",
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.codec_type = AVMEDIA_TYPE_VIDEO,
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.codec_id = AV_CODEC_ID_MJPEG,
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.alloc = jpeg_new_context,
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.free = jpeg_free_context,
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.parse_packet = jpeg_parse_packet,
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.static_payload_id = 26,
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};
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