/* * RTP JPEG-compressed Video Depacketizer, RFC 2435 * Copyright (c) 2012 Samuel Pitoiset * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "avformat.h" #include "rtpdec_formats.h" #include "libavutil/intreadwrite.h" #include "libavcodec/mjpeg.h" /** * RTP/JPEG specific private data. */ struct PayloadContext { AVIOContext *frame; ///< current frame buffer uint32_t timestamp; ///< current frame timestamp int hdr_size; ///< size of the current frame header }; static PayloadContext *jpeg_new_context(void) { return av_mallocz(sizeof(PayloadContext)); } static inline void free_frame_if_needed(PayloadContext *jpeg) { if (jpeg->frame) { uint8_t *p; avio_close_dyn_buf(jpeg->frame, &p); av_free(p); jpeg->frame = NULL; } } static void jpeg_free_context(PayloadContext *jpeg) { free_frame_if_needed(jpeg); av_free(jpeg); } static void jpeg_create_huffman_table(PutBitContext *p, int table_class, int table_id, const uint8_t *bits_table, const uint8_t *value_table) { int i, n = 0; put_bits(p, 8, 0); put_bits(p, 4, table_class); put_bits(p, 4, table_id); for (i = 1; i <= 16; i++) { n += bits_table[i]; put_bits(p, 8, bits_table[i]); } for (i = 0; i < n; i++) { put_bits(p, 8, value_table[i]); } } static int jpeg_create_header(uint8_t *buf, int size, uint32_t type, uint32_t w, uint32_t h, const uint8_t *qtable, int nb_qtable) { PutBitContext pbc; init_put_bits(&pbc, buf, size); /* Convert from blocks to pixels. */ w <<= 3; h <<= 3; /* SOI */ put_marker(&pbc, SOI); /* JFIF header */ put_marker(&pbc, APP0); put_bits(&pbc, 16, 16); avpriv_put_string(&pbc, "JFIF", 1); put_bits(&pbc, 16, 0x0201); put_bits(&pbc, 8, 0); put_bits(&pbc, 16, 1); put_bits(&pbc, 16, 1); put_bits(&pbc, 8, 0); put_bits(&pbc, 8, 0); /* DQT */ put_marker(&pbc, DQT); if (nb_qtable == 2) { put_bits(&pbc, 16, 2 + 2 * (1 + 64)); } else { put_bits(&pbc, 16, 2 + 1 * (1 + 64)); } put_bits(&pbc, 8, 0); /* Each table is an array of 64 values given in zig-zag * order, identical to the format used in a JFIF DQT * marker segment. */ avpriv_copy_bits(&pbc, qtable, 64 * 8); if (nb_qtable == 2) { put_bits(&pbc, 8, 1); avpriv_copy_bits(&pbc, qtable + 64, 64 * 8); } /* DHT */ put_marker(&pbc, DHT); jpeg_create_huffman_table(&pbc, 0, 0, avpriv_mjpeg_bits_dc_luminance, avpriv_mjpeg_val_dc); jpeg_create_huffman_table(&pbc, 0, 1, avpriv_mjpeg_bits_dc_chrominance, avpriv_mjpeg_val_dc); jpeg_create_huffman_table(&pbc, 1, 0, avpriv_mjpeg_bits_ac_luminance, avpriv_mjpeg_val_ac_luminance); jpeg_create_huffman_table(&pbc, 1, 1, avpriv_mjpeg_bits_ac_chrominance, avpriv_mjpeg_val_ac_chrominance); /* SOF0 */ put_marker(&pbc, SOF0); put_bits(&pbc, 16, 17); put_bits(&pbc, 8, 8); put_bits(&pbc, 8, h >> 8); put_bits(&pbc, 8, h); put_bits(&pbc, 8, w >> 8); put_bits(&pbc, 8, w); put_bits(&pbc, 8, 3); put_bits(&pbc, 8, 1); put_bits(&pbc, 8, type ? 34 : 33); put_bits(&pbc, 8, 0); put_bits(&pbc, 8, 2); put_bits(&pbc, 8, 17); put_bits(&pbc, 8, nb_qtable == 2 ? 1 : 0); put_bits(&pbc, 8, 3); put_bits(&pbc, 8, 17); put_bits(&pbc, 8, nb_qtable == 2 ? 1 : 0); /* SOS */ put_marker(&pbc, SOS); put_bits(&pbc, 16, 12); put_bits(&pbc, 8, 3); put_bits(&pbc, 8, 1); put_bits(&pbc, 8, 0); put_bits(&pbc, 8, 2); put_bits(&pbc, 8, 17); put_bits(&pbc, 8, 3); put_bits(&pbc, 8, 17); put_bits(&pbc, 8, 0); put_bits(&pbc, 8, 63); put_bits(&pbc, 8, 0); /* Fill the buffer. */ flush_put_bits(&pbc); /* Return the length in bytes of the JPEG header. */ return put_bits_count(&pbc) / 8; } static int jpeg_parse_packet(AVFormatContext *ctx, PayloadContext *jpeg, AVStream *st, AVPacket *pkt, uint32_t *timestamp, const uint8_t *buf, int len, int flags) { uint8_t type, q, width, height; const uint8_t *qtables = NULL; uint16_t qtable_len; uint32_t off; int ret; if (len < 8) { av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n"); return AVERROR_INVALIDDATA; } /* Parse the main JPEG header. */ off = AV_RB24(buf + 1); /* fragment byte offset */ type = AV_RB8(buf + 4); /* id of jpeg decoder params */ q = AV_RB8(buf + 5); /* quantization factor (or table id) */ width = AV_RB8(buf + 6); /* frame width in 8 pixel blocks */ height = AV_RB8(buf + 7); /* frame height in 8 pixel blocks */ buf += 8; len -= 8; /* Parse the restart marker header. */ if (type > 63) { av_log(ctx, AV_LOG_ERROR, "Unimplemented RTP/JPEG restart marker header.\n"); return AVERROR_PATCHWELCOME; } /* Parse the quantization table header. */ if (q > 127 && off == 0) { uint8_t precision; if (len < 4) { av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n"); return AVERROR_INVALIDDATA; } /* The first byte is reserved for future use. */ precision = AV_RB8(buf + 1); /* size of coefficients */ qtable_len = AV_RB16(buf + 2); /* length in bytes */ buf += 4; len -= 4; if (precision) av_log(ctx, AV_LOG_WARNING, "Only 8-bit precision is supported.\n"); if (q == 255 && qtable_len == 0) { av_log(ctx, AV_LOG_ERROR, "Invalid RTP/JPEG packet. Quantization tables not found.\n"); return AVERROR_INVALIDDATA; } if (qtable_len > 0) { if (len < qtable_len) { av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n"); return AVERROR_INVALIDDATA; } qtables = buf; buf += qtable_len; len -= qtable_len; } } if (off == 0) { /* Start of JPEG data packet. */ uint8_t hdr[1024]; /* Skip the current frame in case of the end packet * has been lost somewhere. */ free_frame_if_needed(jpeg); if ((ret = avio_open_dyn_buf(&jpeg->frame)) < 0) return ret; jpeg->timestamp = *timestamp; if (!qtables) { av_log(ctx, AV_LOG_ERROR, "Unimplemented default quantization tables.\n"); return AVERROR_PATCHWELCOME; } /* Generate a frame and scan headers that can be prepended to the * RTP/JPEG data payload to produce a JPEG compressed image in * interchange format. */ jpeg->hdr_size = jpeg_create_header(hdr, sizeof(hdr), type, width, height, qtables, qtable_len > 64 ? 2 : 1); /* Copy JPEG header to frame buffer. */ avio_write(jpeg->frame, hdr, jpeg->hdr_size); } if (!jpeg->frame) { av_log(ctx, AV_LOG_ERROR, "Received packet without a start chunk; dropping frame.\n"); return AVERROR(EAGAIN); } if (jpeg->timestamp != *timestamp) { /* Skip the current frame if timestamp is incorrect. * A start packet has been lost somewhere. */ free_frame_if_needed(jpeg); av_log(ctx, AV_LOG_ERROR, "RTP timestamps don't match.\n"); return AVERROR_INVALIDDATA; } if (off != avio_tell(jpeg->frame) - jpeg->hdr_size) { av_log(ctx, AV_LOG_ERROR, "Missing packets; dropping frame.\n"); return AVERROR(EAGAIN); } /* Copy data to frame buffer. */ avio_write(jpeg->frame, buf, len); if (flags & RTP_FLAG_MARKER) { /* End of JPEG data packet. */ PutBitContext pbc; uint8_t buf[2]; /* Put EOI marker. */ init_put_bits(&pbc, buf, sizeof(buf)); put_marker(&pbc, EOI); flush_put_bits(&pbc); avio_write(jpeg->frame, buf, sizeof(buf)); /* Prepare the JPEG packet. */ av_init_packet(pkt); pkt->size = avio_close_dyn_buf(jpeg->frame, &pkt->data); if (pkt->size < 0) { av_log(ctx, AV_LOG_ERROR, "Error occured when getting frame buffer.\n"); jpeg->frame = NULL; return pkt->size; } pkt->stream_index = st->index; pkt->destruct = av_destruct_packet; /* Re-init the frame buffer. */ jpeg->frame = NULL; return 0; } return AVERROR(EAGAIN); } RTPDynamicProtocolHandler ff_jpeg_dynamic_handler = { .enc_name = "JPEG", .codec_type = AVMEDIA_TYPE_VIDEO, .codec_id = AV_CODEC_ID_MJPEG, .alloc = jpeg_new_context, .free = jpeg_free_context, .parse_packet = jpeg_parse_packet, .static_payload_id = 26, };