yading@11: /*
yading@11:  * RTP H264 Protocol (RFC3984)
yading@11:  * Copyright (c) 2006 Ryan Martell
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: /**
yading@11:  * @file
yading@11:  * @brief H.264 / RTP Code (RFC3984)
yading@11:  * @author Ryan Martell <rdm4@martellventures.com>
yading@11:  *
yading@11:  * @note Notes:
yading@11:  * Notes:
yading@11:  * This currently supports packetization mode:
yading@11:  * Single Nal Unit Mode (0), or
yading@11:  * Non-Interleaved Mode (1).  It currently does not support
yading@11:  * Interleaved Mode (2). (This requires implementing STAP-B, MTAP16, MTAP24,
yading@11:  *                        FU-B packet types)
yading@11:  */
yading@11: 
yading@11: #include "libavutil/base64.h"
yading@11: #include "libavutil/avstring.h"
yading@11: #include "libavcodec/get_bits.h"
yading@11: #include "avformat.h"
yading@11: 
yading@11: #include "network.h"
yading@11: #include <assert.h>
yading@11: 
yading@11: #include "rtpdec.h"
yading@11: #include "rtpdec_formats.h"
yading@11: 
yading@11: struct PayloadContext {
yading@11:     // sdp setup parameters
yading@11:     uint8_t profile_idc;
yading@11:     uint8_t profile_iop;
yading@11:     uint8_t level_idc;
yading@11:     int packetization_mode;
yading@11: #ifdef DEBUG
yading@11:     int packet_types_received[32];
yading@11: #endif
yading@11: };
yading@11: 
yading@11: #ifdef DEBUG
yading@11: #define COUNT_NAL_TYPE(data, nal) data->packet_types_received[(nal) & 0x1f]++
yading@11: #else
yading@11: #define COUNT_NAL_TYPE(data, nal) do { } while (0)
yading@11: #endif
yading@11: 
yading@11: static const uint8_t start_sequence[] = { 0, 0, 0, 1 };
yading@11: 
yading@11: static int sdp_parse_fmtp_config_h264(AVStream *stream,
yading@11:                                       PayloadContext *h264_data,
yading@11:                                       char *attr, char *value)
yading@11: {
yading@11:     AVCodecContext *codec = stream->codec;
yading@11:     assert(codec->codec_id == AV_CODEC_ID_H264);
yading@11:     assert(h264_data != NULL);
yading@11: 
yading@11:     if (!strcmp(attr, "packetization-mode")) {
yading@11:         av_log(codec, AV_LOG_DEBUG, "RTP Packetization Mode: %d\n", atoi(value));
yading@11:         h264_data->packetization_mode = atoi(value);
yading@11:         /*
yading@11:          * Packetization Mode:
yading@11:          * 0 or not present: Single NAL mode (Only nals from 1-23 are allowed)
yading@11:          * 1: Non-interleaved Mode: 1-23, 24 (STAP-A), 28 (FU-A) are allowed.
yading@11:          * 2: Interleaved Mode: 25 (STAP-B), 26 (MTAP16), 27 (MTAP24), 28 (FU-A),
yading@11:          *                      and 29 (FU-B) are allowed.
yading@11:          */
yading@11:         if (h264_data->packetization_mode > 1)
yading@11:             av_log(codec, AV_LOG_ERROR,
yading@11:                    "Interleaved RTP mode is not supported yet.\n");
yading@11:     } else if (!strcmp(attr, "profile-level-id")) {
yading@11:         if (strlen(value) == 6) {
yading@11:             char buffer[3];
yading@11:             // 6 characters=3 bytes, in hex.
yading@11:             uint8_t profile_idc;
yading@11:             uint8_t profile_iop;
yading@11:             uint8_t level_idc;
yading@11: 
yading@11:             buffer[0]   = value[0];
yading@11:             buffer[1]   = value[1];
yading@11:             buffer[2]   = '\0';
yading@11:             profile_idc = strtol(buffer, NULL, 16);
yading@11:             buffer[0]   = value[2];
yading@11:             buffer[1]   = value[3];
yading@11:             profile_iop = strtol(buffer, NULL, 16);
yading@11:             buffer[0]   = value[4];
yading@11:             buffer[1]   = value[5];
yading@11:             level_idc   = strtol(buffer, NULL, 16);
yading@11: 
yading@11:             av_log(codec, AV_LOG_DEBUG,
yading@11:                    "RTP Profile IDC: %x Profile IOP: %x Level: %x\n",
yading@11:                    profile_idc, profile_iop, level_idc);
yading@11:             h264_data->profile_idc = profile_idc;
yading@11:             h264_data->profile_iop = profile_iop;
yading@11:             h264_data->level_idc   = level_idc;
yading@11:         }
yading@11:     } else if (!strcmp(attr, "sprop-parameter-sets")) {
yading@11:         codec->extradata_size = 0;
yading@11:         av_freep(&codec->extradata);
yading@11: 
yading@11:         while (*value) {
yading@11:             char base64packet[1024];
yading@11:             uint8_t decoded_packet[1024];
yading@11:             int packet_size;
yading@11:             char *dst = base64packet;
yading@11: 
yading@11:             while (*value && *value != ','
yading@11:                    && (dst - base64packet) < sizeof(base64packet) - 1) {
yading@11:                 *dst++ = *value++;
yading@11:             }
yading@11:             *dst++ = '\0';
yading@11: 
yading@11:             if (*value == ',')
yading@11:                 value++;
yading@11: 
yading@11:             packet_size = av_base64_decode(decoded_packet, base64packet,
yading@11:                                            sizeof(decoded_packet));
yading@11:             if (packet_size > 0) {
yading@11:                 uint8_t *dest = av_malloc(packet_size + sizeof(start_sequence) +
yading@11:                                           codec->extradata_size +
yading@11:                                           FF_INPUT_BUFFER_PADDING_SIZE);
yading@11:                 if (!dest) {
yading@11:                     av_log(codec, AV_LOG_ERROR,
yading@11:                            "Unable to allocate memory for extradata!\n");
yading@11:                     return AVERROR(ENOMEM);
yading@11:                 }
yading@11:                 if (codec->extradata_size) {
yading@11:                     memcpy(dest, codec->extradata, codec->extradata_size);
yading@11:                     av_free(codec->extradata);
yading@11:                 }
yading@11: 
yading@11:                 memcpy(dest + codec->extradata_size, start_sequence,
yading@11:                        sizeof(start_sequence));
yading@11:                 memcpy(dest + codec->extradata_size + sizeof(start_sequence),
yading@11:                        decoded_packet, packet_size);
yading@11:                 memset(dest + codec->extradata_size + sizeof(start_sequence) +
yading@11:                        packet_size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
yading@11: 
yading@11:                 codec->extradata       = dest;
yading@11:                 codec->extradata_size += sizeof(start_sequence) + packet_size;
yading@11:             }
yading@11:         }
yading@11:         av_log(codec, AV_LOG_DEBUG, "Extradata set to %p (size: %d)!\n",
yading@11:                codec->extradata, codec->extradata_size);
yading@11:     }
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: // return 0 on packet, no more left, 1 on packet, 1 on partial packet
yading@11: static int h264_handle_packet(AVFormatContext *ctx, PayloadContext *data,
yading@11:                               AVStream *st, AVPacket *pkt, uint32_t *timestamp,
yading@11:                               const uint8_t *buf, int len, uint16_t seq,
yading@11:                               int flags)
yading@11: {
yading@11:     uint8_t nal;
yading@11:     uint8_t type;
yading@11:     int result = 0;
yading@11: 
yading@11:     if (!len) {
yading@11:         av_log(ctx, AV_LOG_ERROR, "Empty H264 RTP packet\n");
yading@11:         return AVERROR_INVALIDDATA;
yading@11:     }
yading@11:     nal  = buf[0];
yading@11:     type = nal & 0x1f;
yading@11: 
yading@11:     assert(data);
yading@11:     assert(buf);
yading@11: 
yading@11:     /* Simplify the case (these are all the nal types used internally by
yading@11:      * the h264 codec). */
yading@11:     if (type >= 1 && type <= 23)
yading@11:         type = 1;
yading@11:     switch (type) {
yading@11:     case 0:                    // undefined, but pass them through
yading@11:     case 1:
yading@11:         av_new_packet(pkt, len + sizeof(start_sequence));
yading@11:         memcpy(pkt->data, start_sequence, sizeof(start_sequence));
yading@11:         memcpy(pkt->data + sizeof(start_sequence), buf, len);
yading@11:         COUNT_NAL_TYPE(data, nal);
yading@11:         break;
yading@11: 
yading@11:     case 24:                   // STAP-A (one packet, multiple nals)
yading@11:         // consume the STAP-A NAL
yading@11:         buf++;
yading@11:         len--;
yading@11:         // first we are going to figure out the total size
yading@11:         {
yading@11:             int pass         = 0;
yading@11:             int total_length = 0;
yading@11:             uint8_t *dst     = NULL;
yading@11: 
yading@11:             for (pass = 0; pass < 2; pass++) {
yading@11:                 const uint8_t *src = buf;
yading@11:                 int src_len        = len;
yading@11: 
yading@11:                 while (src_len > 2) {
yading@11:                     uint16_t nal_size = AV_RB16(src);
yading@11: 
yading@11:                     // consume the length of the aggregate
yading@11:                     src     += 2;
yading@11:                     src_len -= 2;
yading@11: 
yading@11:                     if (nal_size <= src_len) {
yading@11:                         if (pass == 0) {
yading@11:                             // counting
yading@11:                             total_length += sizeof(start_sequence) + nal_size;
yading@11:                         } else {
yading@11:                             // copying
yading@11:                             assert(dst);
yading@11:                             memcpy(dst, start_sequence, sizeof(start_sequence));
yading@11:                             dst += sizeof(start_sequence);
yading@11:                             memcpy(dst, src, nal_size);
yading@11:                             COUNT_NAL_TYPE(data, *src);
yading@11:                             dst += nal_size;
yading@11:                         }
yading@11:                     } else {
yading@11:                         av_log(ctx, AV_LOG_ERROR,
yading@11:                                "nal size exceeds length: %d %d\n", nal_size, src_len);
yading@11:                     }
yading@11: 
yading@11:                     // eat what we handled
yading@11:                     src     += nal_size;
yading@11:                     src_len -= nal_size;
yading@11: 
yading@11:                     if (src_len < 0)
yading@11:                         av_log(ctx, AV_LOG_ERROR,
yading@11:                                "Consumed more bytes than we got! (%d)\n", src_len);
yading@11:                 }
yading@11: 
yading@11:                 if (pass == 0) {
yading@11:                     /* now we know the total size of the packet (with the
yading@11:                      * start sequences added) */
yading@11:                     av_new_packet(pkt, total_length);
yading@11:                     dst = pkt->data;
yading@11:                 } else {
yading@11:                     assert(dst - pkt->data == total_length);
yading@11:                 }
yading@11:             }
yading@11:         }
yading@11:         break;
yading@11: 
yading@11:     case 25:                   // STAP-B
yading@11:     case 26:                   // MTAP-16
yading@11:     case 27:                   // MTAP-24
yading@11:     case 29:                   // FU-B
yading@11:         av_log(ctx, AV_LOG_ERROR,
yading@11:                "Unhandled type (%d) (See RFC for implementation details\n",
yading@11:                type);
yading@11:         result = AVERROR(ENOSYS);
yading@11:         break;
yading@11: 
yading@11:     case 28:                   // FU-A (fragmented nal)
yading@11:         buf++;
yading@11:         len--;                 // skip the fu_indicator
yading@11:         if (len > 1) {
yading@11:             // these are the same as above, we just redo them here for clarity
yading@11:             uint8_t fu_indicator      = nal;
yading@11:             uint8_t fu_header         = *buf;
yading@11:             uint8_t start_bit         = fu_header >> 7;
yading@11:             uint8_t av_unused end_bit = (fu_header & 0x40) >> 6;
yading@11:             uint8_t nal_type          = fu_header & 0x1f;
yading@11:             uint8_t reconstructed_nal;
yading@11: 
yading@11:             // Reconstruct this packet's true nal; only the data follows.
yading@11:             /* The original nal forbidden bit and NRI are stored in this
yading@11:              * packet's nal. */
yading@11:             reconstructed_nal  = fu_indicator & 0xe0;
yading@11:             reconstructed_nal |= nal_type;
yading@11: 
yading@11:             // skip the fu_header
yading@11:             buf++;
yading@11:             len--;
yading@11: 
yading@11:             if (start_bit)
yading@11:                 COUNT_NAL_TYPE(data, nal_type);
yading@11:             if (start_bit) {
yading@11:                 /* copy in the start sequence, and the reconstructed nal */
yading@11:                 av_new_packet(pkt, sizeof(start_sequence) + sizeof(nal) + len);
yading@11:                 memcpy(pkt->data, start_sequence, sizeof(start_sequence));
yading@11:                 pkt->data[sizeof(start_sequence)] = reconstructed_nal;
yading@11:                 memcpy(pkt->data + sizeof(start_sequence) + sizeof(nal), buf, len);
yading@11:             } else {
yading@11:                 av_new_packet(pkt, len);
yading@11:                 memcpy(pkt->data, buf, len);
yading@11:             }
yading@11:         } else {
yading@11:             av_log(ctx, AV_LOG_ERROR, "Too short data for FU-A H264 RTP packet\n");
yading@11:             result = AVERROR_INVALIDDATA;
yading@11:         }
yading@11:         break;
yading@11: 
yading@11:     case 30:                   // undefined
yading@11:     case 31:                   // undefined
yading@11:     default:
yading@11:         av_log(ctx, AV_LOG_ERROR, "Undefined type (%d)\n", type);
yading@11:         result = AVERROR_INVALIDDATA;
yading@11:         break;
yading@11:     }
yading@11: 
yading@11:     pkt->stream_index = st->index;
yading@11: 
yading@11:     return result;
yading@11: }
yading@11: 
yading@11: static PayloadContext *h264_new_context(void)
yading@11: {
yading@11:     return av_mallocz(sizeof(PayloadContext) + FF_INPUT_BUFFER_PADDING_SIZE);
yading@11: }
yading@11: 
yading@11: static void h264_free_context(PayloadContext *data)
yading@11: {
yading@11: #ifdef DEBUG
yading@11:     int ii;
yading@11: 
yading@11:     for (ii = 0; ii < 32; ii++) {
yading@11:         if (data->packet_types_received[ii])
yading@11:             av_log(NULL, AV_LOG_DEBUG, "Received %d packets of type %d\n",
yading@11:                    data->packet_types_received[ii], ii);
yading@11:     }
yading@11: #endif
yading@11: 
yading@11:     av_free(data);
yading@11: }
yading@11: 
yading@11: static int h264_init(AVFormatContext *s, int st_index, PayloadContext *data)
yading@11: {
yading@11:     if (st_index < 0)
yading@11:         return 0;
yading@11:     s->streams[st_index]->need_parsing = AVSTREAM_PARSE_FULL;
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int parse_h264_sdp_line(AVFormatContext *s, int st_index,
yading@11:                                PayloadContext *h264_data, const char *line)
yading@11: {
yading@11:     AVStream *stream;
yading@11:     AVCodecContext *codec;
yading@11:     const char *p = line;
yading@11: 
yading@11:     if (st_index < 0)
yading@11:         return 0;
yading@11: 
yading@11:     stream = s->streams[st_index];
yading@11:     codec  = stream->codec;
yading@11: 
yading@11:     if (av_strstart(p, "framesize:", &p)) {
yading@11:         char buf1[50];
yading@11:         char *dst = buf1;
yading@11: 
yading@11:         // remove the protocol identifier
yading@11:         while (*p && *p == ' ')
yading@11:             p++;                     // strip spaces.
yading@11:         while (*p && *p != ' ')
yading@11:             p++;                     // eat protocol identifier
yading@11:         while (*p && *p == ' ')
yading@11:             p++;                     // strip trailing spaces.
yading@11:         while (*p && *p != '-' && (dst - buf1) < sizeof(buf1) - 1)
yading@11:             *dst++ = *p++;
yading@11:         *dst = '\0';
yading@11: 
yading@11:         // a='framesize:96 320-240'
yading@11:         // set our parameters
yading@11:         codec->width   = atoi(buf1);
yading@11:         codec->height  = atoi(p + 1); // skip the -
yading@11:     } else if (av_strstart(p, "fmtp:", &p)) {
yading@11:         return ff_parse_fmtp(stream, h264_data, p, sdp_parse_fmtp_config_h264);
yading@11:     } else if (av_strstart(p, "cliprect:", &p)) {
yading@11:         // could use this if we wanted.
yading@11:     }
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: RTPDynamicProtocolHandler ff_h264_dynamic_handler = {
yading@11:     .enc_name         = "H264",
yading@11:     .codec_type       = AVMEDIA_TYPE_VIDEO,
yading@11:     .codec_id         = AV_CODEC_ID_H264,
yading@11:     .init             = h264_init,
yading@11:     .parse_sdp_a_line = parse_h264_sdp_line,
yading@11:     .alloc            = h264_new_context,
yading@11:     .free             = h264_free_context,
yading@11:     .parse_packet     = h264_handle_packet
yading@11: };