@@ -7,6 +7,7 @@ version <next>:

 - avplay now exits by default at the end of playback

 - XCB-based screen-grabber

 - creating DASH compatible fragmented MP4, MPEG-DASH segmenting muxer

+- H.261 RTP payload format (RFC 4587) depacketizer and experimental packetizer

 version 11:

@@ -32,6 +32,7 @@ OBJS-$(CONFIG_RTPDEC)                    += rdt.o                       \

                                             rtpdec_amr.o                \

                                             rtpdec_asf.o                \

                                             rtpdec_g726.o               \

+                                            rtpdec_h261.o               \

                                             rtpdec_h263.o               \

                                             rtpdec_h263_rfc2190.o       \

                                             rtpdec_h264.o               \

@@ -290,6 +291,7 @@ OBJS-$(CONFIG_RTP_MUXER)                 += rtp.o         \

                                             rtpenc_aac.o     \

                                             rtpenc_latm.o    \

                                             rtpenc_amr.o     \

+                                            rtpenc_h261.o    \

                                             rtpenc_h263.o    \

                                             rtpenc_h263_rfc2190.o \

                                             rtpenc_hevc.o    \

@@ -66,6 +66,7 @@ void ff_register_rtp_dynamic_payload_handlers(void)

     ff_register_dynamic_payload_handler(&ff_g726_24_dynamic_handler);

     ff_register_dynamic_payload_handler(&ff_g726_32_dynamic_handler);

     ff_register_dynamic_payload_handler(&ff_g726_40_dynamic_handler);

+    ff_register_dynamic_payload_handler(&ff_h261_dynamic_handler);

     ff_register_dynamic_payload_handler(&ff_h263_1998_dynamic_handler);

     ff_register_dynamic_payload_handler(&ff_h263_2000_dynamic_handler);

     ff_register_dynamic_payload_handler(&ff_h263_rfc2190_dynamic_handler);

@@ -41,6 +41,7 @@ extern RTPDynamicProtocolHandler ff_g726_16_dynamic_handler;

 extern RTPDynamicProtocolHandler ff_g726_24_dynamic_handler;

 extern RTPDynamicProtocolHandler ff_g726_32_dynamic_handler;

 extern RTPDynamicProtocolHandler ff_g726_40_dynamic_handler;

+extern RTPDynamicProtocolHandler ff_h261_dynamic_handler;

 extern RTPDynamicProtocolHandler ff_h263_1998_dynamic_handler;

 extern RTPDynamicProtocolHandler ff_h263_2000_dynamic_handler;

 extern RTPDynamicProtocolHandler ff_h263_rfc2190_dynamic_handler;

new file mode 100644

@@ -0,0 +1,202 @@

+/*

+ * RTP parser for H.261 payload format (RFC 4587)

+ * Copyright (c) 2014 Thomas Volkert <thomas@homer-conferencing.com>

+ *

+ * 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 "libavcodec/get_bits.h"

+#include "avformat.h"

+#include "rtpdec_formats.h"

+

+#define RTP_H261_PAYLOAD_HEADER_SIZE 4

+

+struct PayloadContext {

+    AVIOContext *buf;

+    uint8_t      endbyte;

+    int          endbyte_bits;

+    uint32_t     timestamp;

+};

+

+static av_cold PayloadContext *h261_new_context(void)

+{

+    return av_mallocz(sizeof(PayloadContext));

+}

+

+static void h261_free_dyn_buffer(AVIOContext **dyn_buf)

+{

+    uint8_t *ptr_dyn_buffer;

+    avio_close_dyn_buf(*dyn_buf, &ptr_dyn_buffer);

+    av_free(ptr_dyn_buffer);

+    *dyn_buf = NULL;

+}

+

+static av_cold void h261_free_context(PayloadContext *pl_ctx)

+{

+    /* return if context is invalid */

+    if (!pl_ctx)

+        return;

+

+    /* free buffer if it is valid */

+    if (pl_ctx->buf) {

+        h261_free_dyn_buffer(&pl_ctx->buf);

+    }

+

+    /* free context */

+    av_free(pl_ctx);

+}

+

+static av_cold int h261_init(AVFormatContext *ctx, int st_index,

+                             PayloadContext *data)

+{

+    if (st_index < 0)

+        return 0;

+

+    ctx->streams[st_index]->need_parsing = AVSTREAM_PARSE_FULL;

+

+    return 0;

+}

+

+static int h261_handle_packet(AVFormatContext *ctx, PayloadContext *rtp_h261_ctx,

+                              AVStream *st, AVPacket *pkt, uint32_t *timestamp,

+                              const uint8_t *buf, int len, uint16_t seq,

+                              int flags)

+{

+    int sbit, ebit, gobn, mbap, quant;

+    int res;

+

+    /* drop data of previous packets in case of non-continuous (lossy) packet stream */

+    if (rtp_h261_ctx->buf && rtp_h261_ctx->timestamp != *timestamp) {

+        h261_free_dyn_buffer(&rtp_h261_ctx->buf);

+        rtp_h261_ctx->endbyte_bits = 0;

+    }

+

+    /* sanity check for size of input packet: 1 byte payload at least */

+    if (len < RTP_H261_PAYLOAD_HEADER_SIZE + 1) {

+        av_log(ctx, AV_LOG_ERROR, "Too short RTP/H.261 packet, got %d bytes\n", len);

+        return AVERROR_INVALIDDATA;

+    }

+

+    /*

+     * decode the H.261 payload header according to section 4.1 of RFC 4587:

+     * (uses 4 bytes between RTP header and H.261 stream per packet)

+     *

+     *    0                   1                   2                   3

+     *    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1

+     *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

+     *   |SBIT |EBIT |I|V| GOBN  |   MBAP  |  QUANT  |  HMVD   |  VMVD   |

+     *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

+     *

+     *      Start bit position (SBIT): 3 bits

+     *      End bit position (EBIT): 3 bits

+     *      INTRA-frame encoded data (I): 1 bit

+     *      Motion Vector flag (V): 1 bit

+     *      GOB number (GOBN): 4 bits

+     *      Macroblock address predictor (MBAP): 5 bits

+     *      Quantizer (QUANT): 5 bits

+     *      Horizontal motion vector data (HMVD): 5 bits

+     *      Vertical motion vector data (VMVD): 5 bits

+     */

+    sbit  =  (buf[0] >> 5) & 0x07;

+    ebit  =  (buf[0] >> 2) & 0x07;

+    gobn  =  (buf[1] >> 4) & 0x0f;

+    mbap  = ((buf[1] << 1) & 0x1e) | ((buf[2] >> 7) & 0x01);

+    quant =  (buf[2] >> 2) & 0x1f;

+

+    /* pass the H.261 payload header and continue with the actual payload */

+    buf += RTP_H261_PAYLOAD_HEADER_SIZE;

+    len -= RTP_H261_PAYLOAD_HEADER_SIZE;

+

+    /* start frame buffering with new dynamic buffer */

+    if (!rtp_h261_ctx->buf) {

+        /* sanity check: a new frame starts with gobn=0, sbit=0, mbap=0, quant=0 */

+        if (!gobn && !sbit && !mbap && !quant) {

+            res = avio_open_dyn_buf(&rtp_h261_ctx->buf);

+            if (res < 0)

+                return res;

+            /* update the timestamp in the frame packet with the one from the RTP packet */

+            rtp_h261_ctx->timestamp = *timestamp;

+        } else {

+            /* frame not started yet, need more packets */

+            return AVERROR(EAGAIN);

+        }

+    }

+

+    /* do the "byte merging" at the boundaries of two consecutive frame fragments */

+    if (rtp_h261_ctx->endbyte_bits || sbit) {

+        if (rtp_h261_ctx->endbyte_bits == sbit) {

+            rtp_h261_ctx->endbyte     |= buf[0] & (0xff >> sbit);

+            rtp_h261_ctx->endbyte_bits = 0;

+            buf++;

+            len--;

+            avio_w8(rtp_h261_ctx->buf, rtp_h261_ctx->endbyte);

+        } else {

+            /* ebit/sbit values inconsistent, assuming packet loss */

+            GetBitContext gb;

+            init_get_bits(&gb, buf, len*8 - ebit);

+            skip_bits(&gb, sbit);

+            if (rtp_h261_ctx->endbyte_bits) {

+                rtp_h261_ctx->endbyte |= get_bits(&gb, 8 - rtp_h261_ctx->endbyte_bits);

+                avio_w8(rtp_h261_ctx->buf, rtp_h261_ctx->endbyte);

+            }

+            while (get_bits_left(&gb) >= 8)

+                avio_w8(rtp_h261_ctx->buf, get_bits(&gb, 8));

+            rtp_h261_ctx->endbyte_bits = get_bits_left(&gb);

+            if (rtp_h261_ctx->endbyte_bits)

+                rtp_h261_ctx->endbyte = get_bits(&gb, rtp_h261_ctx->endbyte_bits) <<

+                                        (8 - rtp_h261_ctx->endbyte_bits);

+            ebit = 0;

+            len  = 0;

+        }

+    }

+    if (ebit) {

+        if (len > 0)

+            avio_write(rtp_h261_ctx->buf, buf, len - 1);

+        rtp_h261_ctx->endbyte_bits = 8 - ebit;

+        rtp_h261_ctx->endbyte      = buf[len - 1] & (0xff << ebit);

+    } else {

+        avio_write(rtp_h261_ctx->buf, buf, len);

+    }

+

+    /* RTP marker bit means: last fragment of current frame was received;

+       otherwise, an additional fragment is needed for the current frame */

+    if (!(flags & RTP_FLAG_MARKER))

+        return AVERROR(EAGAIN);

+

+    /* write the completed last byte from the "byte merging" */

+    if (rtp_h261_ctx->endbyte_bits)

+        avio_w8(rtp_h261_ctx->buf, rtp_h261_ctx->endbyte);

+    rtp_h261_ctx->endbyte_bits = 0;

+

+    /* close frame buffering and create resulting A/V packet */

+    res = ff_rtp_finalize_packet(pkt, &rtp_h261_ctx->buf, st->index);

+    if (res < 0)

+        return res;

+

+    return 0;

+}

+

+RTPDynamicProtocolHandler ff_h261_dynamic_handler = {

+    .enc_name          = "H261",

+    .codec_type        = AVMEDIA_TYPE_VIDEO,

+    .codec_id          = AV_CODEC_ID_H261,

+    .init              = h261_init,

+    .alloc             = h261_new_context,

+    .free              = h261_free_context,

+    .parse_packet      = h261_handle_packet,

+    .static_payload_id = 31,

+};

@@ -49,6 +49,7 @@ static const AVClass rtp_muxer_class = {

 static int is_supported(enum AVCodecID id)

 {

     switch(id) {

+    case AV_CODEC_ID_H261:

     case AV_CODEC_ID_H263:

     case AV_CODEC_ID_H263P:

     case AV_CODEC_ID_H264:

@@ -88,7 +89,7 @@ static int is_supported(enum AVCodecID id)

 static int rtp_write_header(AVFormatContext *s1)

 {

     RTPMuxContext *s = s1->priv_data;

-    int n;

+    int n, ret = AVERROR(EINVAL);

     AVStream *st;

     if (s1->nb_streams != 1) {

@@ -191,6 +192,17 @@ static int rtp_write_header(AVFormatContext *s1)

         s->max_payload_size = n * TS_PACKET_SIZE;

         s->buf_ptr = s->buf;

         break;

+    case AV_CODEC_ID_H261:

+        if (s1->strict_std_compliance > FF_COMPLIANCE_EXPERIMENTAL) {

+            av_log(s, AV_LOG_ERROR,

+                   "Packetizing H261 is experimental and produces incorrect "

+                   "packetization for cases where GOBs don't fit into packets "

+                   "(even though most receivers may handle it just fine). "

+                   "Please set -f_strict experimental in order to enable it.\n");

+            ret = AVERROR_EXPERIMENTAL;

+            goto fail;

+        }

+        break;

     case AV_CODEC_ID_H264:

         /* check for H.264 MP4 syntax */

         if (st->codec->extradata_size > 4 && st->codec->extradata[0] == 1) {

@@ -273,7 +285,7 @@ defaultcase:

 fail:

     av_freep(&s->buf);

-    return AVERROR(EINVAL);

+    return ret;

 }

 /* send an rtcp sender report packet */

@@ -567,6 +579,9 @@ static int rtp_write_packet(AVFormatContext *s1, AVPacket *pkt)

     case AV_CODEC_ID_H264:

         ff_rtp_send_h264(s1, pkt->data, size);

         break;

+    case AV_CODEC_ID_H261:

+        ff_rtp_send_h261(s1, pkt->data, size);

+        break;

     case AV_CODEC_ID_H263:

         if (s->flags & FF_RTP_FLAG_RFC2190) {

             int mb_info_size = 0;

@@ -81,6 +81,7 @@ typedef struct RTPMuxContext RTPMuxContext;

 void ff_rtp_send_data(AVFormatContext *s1, const uint8_t *buf1, int len, int m);

 void ff_rtp_send_h264(AVFormatContext *s1, const uint8_t *buf1, int size);

+void ff_rtp_send_h261(AVFormatContext *s1, const uint8_t *buf1, int size);

 void ff_rtp_send_h263(AVFormatContext *s1, const uint8_t *buf1, int size);

 void ff_rtp_send_h263_rfc2190(AVFormatContext *s1, const uint8_t *buf1, int size,

                               const uint8_t *mb_info, int mb_info_size);

new file mode 100644

@@ -0,0 +1,102 @@

+/*

+ * RTP packetization for H.261 video (RFC 4587)

+ * Copyright (c) 2014 Thomas Volkert <thomas@homer-conferencing.com>

+ *

+ * 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 "rtpenc.h"

+

+#define RTP_H261_HEADER_SIZE 4

+

+static const uint8_t *find_resync_marker_reverse(const uint8_t *restrict start,

+                                                 const uint8_t *restrict end)

+{

+    const uint8_t *p = end - 1;

+    start += 1; /* Make sure we never return the original start. */

+    for (; p > start; p--) {

+        if (p[0] == 0 && p[1] == 1)

+            return p;

+    }

+    return end;

+}

+

+void ff_rtp_send_h261(AVFormatContext *ctx, const uint8_t *frame_buf, int frame_size)

+{

+    int cur_frame_size;

+    int last_packet_of_frame;

+    RTPMuxContext *rtp_ctx = ctx->priv_data;

+

+    /* use the default 90 KHz time stamp */

+    rtp_ctx->timestamp = rtp_ctx->cur_timestamp;

+

+    /* continue as long as not all frame data is processed */

+    while (frame_size > 0) {

+        /*

+         * encode the H.261 payload header according to section 4.1 of RFC 4587:

+         * (uses 4 bytes between RTP header and H.261 stream per packet)

+         *

+         *    0                   1                   2                   3

+         *    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1

+         *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

+         *   |SBIT |EBIT |I|V| GOBN  |   MBAP  |  QUANT  |  HMVD   |  VMVD   |

+         *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

+         *

+         *      Start bit position (SBIT): 3 bits

+         *      End bit position (EBIT): 3 bits

+         *      INTRA-frame encoded data (I): 1 bit

+         *      Motion Vector flag (V): 1 bit

+         *      GOB number (GOBN): 4 bits

+         *      Macroblock address predictor (MBAP): 5 bits

+         *      Quantizer (QUANT): 5 bits

+         *      Horizontal motion vector data (HMVD): 5 bits

+         *      Vertical motion vector data (VMVD): 5 bits

+         */

+        rtp_ctx->buf[0] = 1; /* sbit=0, ebit=0, i=0, v=1 */

+        rtp_ctx->buf[1] = 0; /* gobn=0, mbap=0 */

+        rtp_ctx->buf[2] = 0; /* quant=0, hmvd=5 */

+        rtp_ctx->buf[3] = 0; /* vmvd=0 */

+        if (frame_size < 2 || frame_buf[0] != 0 || frame_buf[1] != 1) {

+            /* A full, correct fix for this would be to make the H261 encoder

+             * support inserting extra GOB headers (triggered by setting e.g.

+             * "-ps 1"), and including information about macroblock boundaries

+             * (such as for h263_rfc2190). */

+            av_log(ctx, AV_LOG_WARNING,

+                   "RTP/H261 packet not cut at a GOB boundary, not signaled correctly\n");

+        }

+

+        cur_frame_size = FFMIN(rtp_ctx->max_payload_size - RTP_H261_HEADER_SIZE, frame_size);

+

+        /* look for a better place to split the frame into packets */

+        if (cur_frame_size < frame_size) {

+            const uint8_t *packet_end = find_resync_marker_reverse(frame_buf,

+                                                                   frame_buf + cur_frame_size);

+            cur_frame_size = packet_end - frame_buf;

+        }

+

+        /* calculate the "marker" bit for the RTP header */

+        last_packet_of_frame = cur_frame_size == frame_size;

+

+        /* complete and send RTP packet */

+        memcpy(&rtp_ctx->buf[RTP_H261_HEADER_SIZE], frame_buf, cur_frame_size);

+        ff_rtp_send_data(ctx, rtp_ctx->buf, RTP_H261_HEADER_SIZE + cur_frame_size, last_packet_of_frame);

+

+        frame_buf  += cur_frame_size;

+        frame_size -= cur_frame_size;

+    }

+}

@@ -498,6 +498,20 @@ static char *sdp_write_media_attributes(char *buff, int size, AVCodecContext *c,

                                      payload_type, mode, config ? config : "");

             break;

         }

+        case AV_CODEC_ID_H261:

+        {

+            const char *pic_fmt = NULL;

+            /* only QCIF and CIF are specified as supported in RFC 4587 */

+            if (c->width == 176 && c->height == 144)

+                pic_fmt = "QCIF=1";

+            else if (c->width == 352 && c->height == 288)

+                pic_fmt = "CIF=1";

+            if (payload_type >= RTP_PT_PRIVATE)

+                av_strlcatf(buff, size, "a=rtpmap:%d H261/90000\r\n", payload_type);

+            if (pic_fmt)

+                av_strlcatf(buff, size, "a=fmtp:%d %s\r\n", payload_type, pic_fmt);

+            break;

+        }

         case AV_CODEC_ID_H263:

         case AV_CODEC_ID_H263P:

             /* a=framesize is required by 3GPP TS 26.234 (PSS). It

@@ -30,8 +30,8 @@

 #include "libavutil/version.h"

 #define LIBAVFORMAT_VERSION_MAJOR 56

-#define LIBAVFORMAT_VERSION_MINOR  7

-#define LIBAVFORMAT_VERSION_MICRO  2

+#define LIBAVFORMAT_VERSION_MINOR  8

+#define LIBAVFORMAT_VERSION_MICRO  0

 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \

                                                LIBAVFORMAT_VERSION_MINOR, \