rtp: Depacketization of JPEG (RFC 2435)

Signed-off-by: Martin Storsjö <martin@martin.st>

1 files changed, 331 insertions, 0 deletions

diff --git a/libavformat/rtpdec_jpeg.c b/libavformat/rtpdec_jpeg.c
new file mode 100644
index 0000000000..c77ecbfdef
--- /dev/null
+++ b/libavformat/rtpdec_jpeg.c
@@ -0,0 +1,331 @@
+/*
+ * RTP JPEG-compressed Video Depacketizer, RFC 2435
+ * Copyright (c) 2012 Samuel Pitoiset
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; 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,
+};