FFmpeg: libavformat/rtmppkt.c Source File

00001 /*
00002  * RTMP input format
00003  * Copyright (c) 2009 Kostya Shishkov
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include "libavcodec/bytestream.h"
00023 #include "libavutil/avstring.h"
00024 #include "libavutil/intfloat_readwrite.h"
00025 #include "avformat.h"
00026 
00027 #include "rtmppkt.h"
00028 #include "flv.h"
00029 #include "url.h"
00030 
00031 void ff_amf_write_bool(uint8_t **dst, int val)
00032 {
00033     bytestream_put_byte(dst, AMF_DATA_TYPE_BOOL);
00034     bytestream_put_byte(dst, val);
00035 }
00036 
00037 void ff_amf_write_number(uint8_t **dst, double val)
00038 {
00039     bytestream_put_byte(dst, AMF_DATA_TYPE_NUMBER);
00040     bytestream_put_be64(dst, av_dbl2int(val));
00041 }
00042 
00043 void ff_amf_write_string(uint8_t **dst, const char *str)
00044 {
00045     bytestream_put_byte(dst, AMF_DATA_TYPE_STRING);
00046     bytestream_put_be16(dst, strlen(str));
00047     bytestream_put_buffer(dst, str, strlen(str));
00048 }
00049 
00050 void ff_amf_write_null(uint8_t **dst)
00051 {
00052     bytestream_put_byte(dst, AMF_DATA_TYPE_NULL);
00053 }
00054 
00055 void ff_amf_write_object_start(uint8_t **dst)
00056 {
00057     bytestream_put_byte(dst, AMF_DATA_TYPE_OBJECT);
00058 }
00059 
00060 void ff_amf_write_field_name(uint8_t **dst, const char *str)
00061 {
00062     bytestream_put_be16(dst, strlen(str));
00063     bytestream_put_buffer(dst, str, strlen(str));
00064 }
00065 
00066 void ff_amf_write_object_end(uint8_t **dst)
00067 {
00068     /* first two bytes are field name length = 0,
00069      * AMF object should end with it and end marker
00070      */
00071     bytestream_put_be24(dst, AMF_DATA_TYPE_OBJECT_END);
00072 }
00073 
00074 int ff_rtmp_packet_read(URLContext *h, RTMPPacket *p,
00075                         int chunk_size, RTMPPacket *prev_pkt)
00076 {
00077     uint8_t hdr, t, buf[16];
00078     int channel_id, timestamp, data_size, offset = 0;
00079     uint32_t extra = 0;
00080     enum RTMPPacketType type;
00081     int size = 0;
00082 
00083     if (ffurl_read(h, &hdr, 1) != 1)
00084         return AVERROR(EIO);
00085     size++;
00086     channel_id = hdr & 0x3F;
00087 
00088     if (channel_id < 2) { //special case for channel number >= 64
00089         buf[1] = 0;
00090         if (ffurl_read_complete(h, buf, channel_id + 1) != channel_id + 1)
00091             return AVERROR(EIO);
00092         size += channel_id + 1;
00093         channel_id = AV_RL16(buf) + 64;
00094     }
00095     data_size = prev_pkt[channel_id].data_size;
00096     type      = prev_pkt[channel_id].type;
00097     extra     = prev_pkt[channel_id].extra;
00098 
00099     hdr >>= 6;
00100     if (hdr == RTMP_PS_ONEBYTE) {
00101         timestamp = prev_pkt[channel_id].ts_delta;
00102     } else {
00103         if (ffurl_read_complete(h, buf, 3) != 3)
00104             return AVERROR(EIO);
00105         size += 3;
00106         timestamp = AV_RB24(buf);
00107         if (hdr != RTMP_PS_FOURBYTES) {
00108             if (ffurl_read_complete(h, buf, 3) != 3)
00109                 return AVERROR(EIO);
00110             size += 3;
00111             data_size = AV_RB24(buf);
00112             if (ffurl_read_complete(h, buf, 1) != 1)
00113                 return AVERROR(EIO);
00114             size++;
00115             type = buf[0];
00116             if (hdr == RTMP_PS_TWELVEBYTES) {
00117                 if (ffurl_read_complete(h, buf, 4) != 4)
00118                     return AVERROR(EIO);
00119                 size += 4;
00120                 extra = AV_RL32(buf);
00121             }
00122         }
00123         if (timestamp == 0xFFFFFF) {
00124             if (ffurl_read_complete(h, buf, 4) != 4)
00125                 return AVERROR(EIO);
00126             timestamp = AV_RB32(buf);
00127         }
00128     }
00129     if (hdr != RTMP_PS_TWELVEBYTES)
00130         timestamp += prev_pkt[channel_id].timestamp;
00131 
00132     if (ff_rtmp_packet_create(p, channel_id, type, timestamp, data_size))
00133         return -1;
00134     p->extra = extra;
00135     // save history
00136     prev_pkt[channel_id].channel_id = channel_id;
00137     prev_pkt[channel_id].type       = type;
00138     prev_pkt[channel_id].data_size  = data_size;
00139     prev_pkt[channel_id].ts_delta   = timestamp - prev_pkt[channel_id].timestamp;
00140     prev_pkt[channel_id].timestamp  = timestamp;
00141     prev_pkt[channel_id].extra      = extra;
00142     while (data_size > 0) {
00143         int toread = FFMIN(data_size, chunk_size);
00144         if (ffurl_read_complete(h, p->data + offset, toread) != toread) {
00145             ff_rtmp_packet_destroy(p);
00146             return AVERROR(EIO);
00147         }
00148         data_size -= chunk_size;
00149         offset    += chunk_size;
00150         size      += chunk_size;
00151         if (data_size > 0) {
00152             ffurl_read_complete(h, &t, 1); //marker
00153             size++;
00154             if (t != (0xC0 + channel_id))
00155                 return -1;
00156         }
00157     }
00158     return size;
00159 }
00160 
00161 int ff_rtmp_packet_write(URLContext *h, RTMPPacket *pkt,
00162                          int chunk_size, RTMPPacket *prev_pkt)
00163 {
00164     uint8_t pkt_hdr[16], *p = pkt_hdr;
00165     int mode = RTMP_PS_TWELVEBYTES;
00166     int off = 0;
00167     int size = 0;
00168 
00169     pkt->ts_delta = pkt->timestamp - prev_pkt[pkt->channel_id].timestamp;
00170 
00171     //if channel_id = 0, this is first presentation of prev_pkt, send full hdr.
00172     if (prev_pkt[pkt->channel_id].channel_id &&
00173         pkt->extra == prev_pkt[pkt->channel_id].extra) {
00174         if (pkt->type == prev_pkt[pkt->channel_id].type &&
00175             pkt->data_size == prev_pkt[pkt->channel_id].data_size) {
00176             mode = RTMP_PS_FOURBYTES;
00177             if (pkt->ts_delta == prev_pkt[pkt->channel_id].ts_delta)
00178                 mode = RTMP_PS_ONEBYTE;
00179         } else {
00180             mode = RTMP_PS_EIGHTBYTES;
00181         }
00182     }
00183 
00184     if (pkt->channel_id < 64) {
00185         bytestream_put_byte(&p, pkt->channel_id | (mode << 6));
00186     } else if (pkt->channel_id < 64 + 256) {
00187         bytestream_put_byte(&p, 0               | (mode << 6));
00188         bytestream_put_byte(&p, pkt->channel_id - 64);
00189     } else {
00190         bytestream_put_byte(&p, 1               | (mode << 6));
00191         bytestream_put_le16(&p, pkt->channel_id - 64);
00192     }
00193     if (mode != RTMP_PS_ONEBYTE) {
00194         uint32_t timestamp = pkt->timestamp;
00195         if (mode != RTMP_PS_TWELVEBYTES)
00196             timestamp = pkt->ts_delta;
00197         bytestream_put_be24(&p, timestamp >= 0xFFFFFF ? 0xFFFFFF : timestamp);
00198         if (mode != RTMP_PS_FOURBYTES) {
00199             bytestream_put_be24(&p, pkt->data_size);
00200             bytestream_put_byte(&p, pkt->type);
00201             if (mode == RTMP_PS_TWELVEBYTES)
00202                 bytestream_put_le32(&p, pkt->extra);
00203         }
00204         if (timestamp >= 0xFFFFFF)
00205             bytestream_put_be32(&p, timestamp);
00206     }
00207     // save history
00208     prev_pkt[pkt->channel_id].channel_id = pkt->channel_id;
00209     prev_pkt[pkt->channel_id].type       = pkt->type;
00210     prev_pkt[pkt->channel_id].data_size  = pkt->data_size;
00211     prev_pkt[pkt->channel_id].timestamp  = pkt->timestamp;
00212     if (mode != RTMP_PS_TWELVEBYTES) {
00213         prev_pkt[pkt->channel_id].ts_delta   = pkt->ts_delta;
00214     } else {
00215         prev_pkt[pkt->channel_id].ts_delta   = pkt->timestamp;
00216     }
00217     prev_pkt[pkt->channel_id].extra      = pkt->extra;
00218 
00219     ffurl_write(h, pkt_hdr, p-pkt_hdr);
00220     size = p - pkt_hdr + pkt->data_size;
00221     while (off < pkt->data_size) {
00222         int towrite = FFMIN(chunk_size, pkt->data_size - off);
00223         ffurl_write(h, pkt->data + off, towrite);
00224         off += towrite;
00225         if (off < pkt->data_size) {
00226             uint8_t marker = 0xC0 | pkt->channel_id;
00227             ffurl_write(h, &marker, 1);
00228             size++;
00229         }
00230     }
00231     return size;
00232 }
00233 
00234 int ff_rtmp_packet_create(RTMPPacket *pkt, int channel_id, RTMPPacketType type,
00235                           int timestamp, int size)
00236 {
00237     if (size) {
00238         pkt->data = av_malloc(size);
00239         if (!pkt->data)
00240             return AVERROR(ENOMEM);
00241     }
00242     pkt->data_size  = size;
00243     pkt->channel_id = channel_id;
00244     pkt->type       = type;
00245     pkt->timestamp  = timestamp;
00246     pkt->extra      = 0;
00247     pkt->ts_delta   = 0;
00248 
00249     return 0;
00250 }
00251 
00252 void ff_rtmp_packet_destroy(RTMPPacket *pkt)
00253 {
00254     if (!pkt)
00255         return;
00256     av_freep(&pkt->data);
00257     pkt->data_size = 0;
00258 }
00259 
00260 int ff_amf_tag_size(const uint8_t *data, const uint8_t *data_end)
00261 {
00262     const uint8_t *base = data;
00263 
00264     if (data >= data_end)
00265         return -1;
00266     switch (*data++) {
00267     case AMF_DATA_TYPE_NUMBER:      return 9;
00268     case AMF_DATA_TYPE_BOOL:        return 2;
00269     case AMF_DATA_TYPE_STRING:      return 3 + AV_RB16(data);
00270     case AMF_DATA_TYPE_LONG_STRING: return 5 + AV_RB32(data);
00271     case AMF_DATA_TYPE_NULL:        return 1;
00272     case AMF_DATA_TYPE_ARRAY:
00273         data += 4;
00274     case AMF_DATA_TYPE_OBJECT:
00275         for (;;) {
00276             int size = bytestream_get_be16(&data);
00277             int t;
00278             if (!size) {
00279                 data++;
00280                 break;
00281             }
00282             if (data + size >= data_end || data + size < data)
00283                 return -1;
00284             data += size;
00285             t = ff_amf_tag_size(data, data_end);
00286             if (t < 0 || data + t >= data_end)
00287                 return -1;
00288             data += t;
00289         }
00290         return data - base;
00291     case AMF_DATA_TYPE_OBJECT_END:  return 1;
00292     default:                        return -1;
00293     }
00294 }
00295 
00296 int ff_amf_get_field_value(const uint8_t *data, const uint8_t *data_end,
00297                            const uint8_t *name, uint8_t *dst, int dst_size)
00298 {
00299     int namelen = strlen(name);
00300     int len;
00301 
00302     while (*data != AMF_DATA_TYPE_OBJECT && data < data_end) {
00303         len = ff_amf_tag_size(data, data_end);
00304         if (len < 0)
00305             len = data_end - data;
00306         data += len;
00307     }
00308     if (data_end - data < 3)
00309         return -1;
00310     data++;
00311     for (;;) {
00312         int size = bytestream_get_be16(&data);
00313         if (!size)
00314             break;
00315         if (data + size >= data_end || data + size < data)
00316             return -1;
00317         data += size;
00318         if (size == namelen && !memcmp(data-size, name, namelen)) {
00319             switch (*data++) {
00320             case AMF_DATA_TYPE_NUMBER:
00321                 snprintf(dst, dst_size, "%g", av_int2dbl(AV_RB64(data)));
00322                 break;
00323             case AMF_DATA_TYPE_BOOL:
00324                 snprintf(dst, dst_size, "%s", *data ? "true" : "false");
00325                 break;
00326             case AMF_DATA_TYPE_STRING:
00327                 len = bytestream_get_be16(&data);
00328                 av_strlcpy(dst, data, FFMIN(len+1, dst_size));
00329                 break;
00330             default:
00331                 return -1;
00332             }
00333             return 0;
00334         }
00335         len = ff_amf_tag_size(data, data_end);
00336         if (len < 0 || data + len >= data_end || data + len < data)
00337             return -1;
00338         data += len;
00339     }
00340     return -1;
00341 }
00342 
00343 static const char* rtmp_packet_type(int type)
00344 {
00345     switch (type) {
00346     case RTMP_PT_CHUNK_SIZE:     return "chunk size";
00347     case RTMP_PT_BYTES_READ:     return "bytes read";
00348     case RTMP_PT_PING:           return "ping";
00349     case RTMP_PT_SERVER_BW:      return "server bandwidth";
00350     case RTMP_PT_CLIENT_BW:      return "client bandwidth";
00351     case RTMP_PT_AUDIO:          return "audio packet";
00352     case RTMP_PT_VIDEO:          return "video packet";
00353     case RTMP_PT_FLEX_STREAM:    return "Flex shared stream";
00354     case RTMP_PT_FLEX_OBJECT:    return "Flex shared object";
00355     case RTMP_PT_FLEX_MESSAGE:   return "Flex shared message";
00356     case RTMP_PT_NOTIFY:         return "notification";
00357     case RTMP_PT_SHARED_OBJ:     return "shared object";
00358     case RTMP_PT_INVOKE:         return "invoke";
00359     case RTMP_PT_METADATA:       return "metadata";
00360     default:                     return "unknown";
00361     }
00362 }
00363 
00364 static void ff_amf_tag_contents(void *ctx, const uint8_t *data, const uint8_t *data_end)
00365 {
00366     int size;
00367     char buf[1024];
00368 
00369     if (data >= data_end)
00370         return;
00371     switch (*data++) {
00372     case AMF_DATA_TYPE_NUMBER:
00373         av_log(ctx, AV_LOG_DEBUG, " number %g\n", av_int2dbl(AV_RB64(data)));
00374         return;
00375     case AMF_DATA_TYPE_BOOL:
00376         av_log(ctx, AV_LOG_DEBUG, " bool %d\n", *data);
00377         return;
00378     case AMF_DATA_TYPE_STRING:
00379     case AMF_DATA_TYPE_LONG_STRING:
00380         if (data[-1] == AMF_DATA_TYPE_STRING) {
00381             size = bytestream_get_be16(&data);
00382         } else {
00383             size = bytestream_get_be32(&data);
00384         }
00385         size = FFMIN(size, 1023);
00386         memcpy(buf, data, size);
00387         buf[size] = 0;
00388         av_log(ctx, AV_LOG_DEBUG, " string '%s'\n", buf);
00389         return;
00390     case AMF_DATA_TYPE_NULL:
00391         av_log(ctx, AV_LOG_DEBUG, " NULL\n");
00392         return;
00393     case AMF_DATA_TYPE_ARRAY:
00394         data += 4;
00395     case AMF_DATA_TYPE_OBJECT:
00396         av_log(ctx, AV_LOG_DEBUG, " {\n");
00397         for (;;) {
00398             int size = bytestream_get_be16(&data);
00399             int t;
00400             memcpy(buf, data, size);
00401             buf[size] = 0;
00402             if (!size) {
00403                 av_log(ctx, AV_LOG_DEBUG, " }\n");
00404                 data++;
00405                 break;
00406             }
00407             if (data + size >= data_end || data + size < data)
00408                 return;
00409             data += size;
00410             av_log(ctx, AV_LOG_DEBUG, "  %s: ", buf);
00411             ff_amf_tag_contents(ctx, data, data_end);
00412             t = ff_amf_tag_size(data, data_end);
00413             if (t < 0 || data + t >= data_end)
00414                 return;
00415             data += t;
00416         }
00417         return;
00418     case AMF_DATA_TYPE_OBJECT_END:
00419         av_log(ctx, AV_LOG_DEBUG, " }\n");
00420         return;
00421     default:
00422         return;
00423     }
00424 }
00425 
00426 void ff_rtmp_packet_dump(void *ctx, RTMPPacket *p)
00427 {
00428     av_log(ctx, AV_LOG_DEBUG, "RTMP packet type '%s'(%d) for channel %d, timestamp %d, extra field %d size %d\n",
00429            rtmp_packet_type(p->type), p->type, p->channel_id, p->timestamp, p->extra, p->data_size);
00430     if (p->type == RTMP_PT_INVOKE || p->type == RTMP_PT_NOTIFY) {
00431         uint8_t *src = p->data, *src_end = p->data + p->data_size;
00432         while (src < src_end) {
00433             int sz;
00434             ff_amf_tag_contents(ctx, src, src_end);
00435             sz = ff_amf_tag_size(src, src_end);
00436             if (sz < 0)
00437                 break;
00438             src += sz;
00439         }
00440     } else if (p->type == RTMP_PT_SERVER_BW){
00441         av_log(ctx, AV_LOG_DEBUG, "Server BW = %d\n", AV_RB32(p->data));
00442     } else if (p->type == RTMP_PT_CLIENT_BW){
00443         av_log(ctx, AV_LOG_DEBUG, "Client BW = %d\n", AV_RB32(p->data));
00444     } else if (p->type != RTMP_PT_AUDIO && p->type != RTMP_PT_VIDEO && p->type != RTMP_PT_METADATA) {
00445         int i;
00446         for (i = 0; i < p->data_size; i++)
00447             av_log(ctx, AV_LOG_DEBUG, " %02X", p->data[i]);
00448         av_log(ctx, AV_LOG_DEBUG, "\n");
00449     }
00450 }