flv: support stream text data as onTextData

Adobe specifies onTextData as the standard message to use to deliver
text information.
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

libavformat/flvdec.c

@@ -66,6 +66,17 @@ static int flv_probe(AVProbeData *p)
     return 0;
 }
 
+static AVStream *create_stream(AVFormatContext *s, int tag, int codec_type)
+{
+    AVStream *st = avformat_new_stream(s, NULL);
+    if (!st)
+        return NULL;
+    st->id = tag;
+    st->codec->codec_type = codec_type;
+    avpriv_set_pts_info(st, 32, 1, 1000); /* 32 bit pts in ms */
+    return st;
+}
+
 static void flv_set_audio_codec(AVFormatContext *s, AVStream *astream, AVCodecContext *acodec, int flv_codecid) {
     switch(flv_codecid) {
         //no distinction between S16 and S8 PCM codec flags
@@ -302,6 +313,12 @@ static int amf_parse_object(AVFormatContext *s, AVStream *astream, AVStream *vst
                 vcodec->bit_rate = num_val * 1024.0;
             else if (!strcmp(key, "audiodatarate") && acodec && 0 <= (int)(num_val * 1024.0))
                 acodec->bit_rate = num_val * 1024.0;
+            else if (!strcmp(key, "datastream")) {
+                AVStream *st = create_stream(s, 2, AVMEDIA_TYPE_DATA);
+                if (!st)
+                    return AVERROR(ENOMEM);
+                st->codec->codec_id = CODEC_ID_TEXT;
+            }
         }
 
         if (!strcmp(key, "duration")        ||
@@ -344,7 +361,14 @@ static int flv_read_metabody(AVFormatContext *s, int64_t next_pos) {
 
     //first object needs to be "onMetaData" string
     type = avio_r8(ioc);
-    if(type != AMF_DATA_TYPE_STRING || amf_get_string(ioc, buffer, sizeof(buffer)) < 0 || strcmp(buffer, "onMetaData"))
+    if (type != AMF_DATA_TYPE_STRING ||
+        amf_get_string(ioc, buffer, sizeof(buffer)) < 0)
+        return -1;
+
+    if (!strcmp(buffer, "onTextData"))
+        return 1;
+
+    if (strcmp(buffer, "onMetaData"))
         return -1;
 
     //find the streams now so that amf_parse_object doesn't need to do the lookup every time it is called.
@@ -361,16 +385,6 @@ static int flv_read_metabody(AVFormatContext *s, int64_t next_pos) {
     return 0;
 }
 
-static AVStream *create_stream(AVFormatContext *s, int is_audio){
-    AVStream *st = avformat_new_stream(s, NULL);
-    if (!st)
-        return NULL;
-    st->id = is_audio;
-    st->codec->codec_type = is_audio ? AVMEDIA_TYPE_AUDIO : AVMEDIA_TYPE_VIDEO;
-    avpriv_set_pts_info(st, 32, 1, 1000); /* 32 bit pts in ms */
-    return st;
-}
-
 static int flv_read_header(AVFormatContext *s)
 {
     int offset, flags;
@@ -389,11 +403,11 @@ static int flv_read_header(AVFormatContext *s)
         s->ctx_flags |= AVFMTCTX_NOHEADER;
 
     if(flags & FLV_HEADER_FLAG_HASVIDEO){
-        if(!create_stream(s, 0))
+        if(!create_stream(s, 0, AVMEDIA_TYPE_VIDEO))
             return AVERROR(ENOMEM);
     }
     if(flags & FLV_HEADER_FLAG_HASAUDIO){
-        if(!create_stream(s, 1))
+        if(!create_stream(s, 1, AVMEDIA_TYPE_AUDIO))
             return AVERROR(ENOMEM);
     }
 
@@ -453,6 +467,65 @@ static void clear_index_entries(AVFormatContext *s, int64_t pos)
     }
 }
 
+
+static int flv_data_packet(AVFormatContext *s, AVPacket *pkt,
+                           int64_t dts, int64_t next)
+{
+    int ret = AVERROR_INVALIDDATA, i;
+    AVIOContext *pb = s->pb;
+    AVStream *st = NULL;
+    AMFDataType type;
+    char buf[20];
+    int length;
+
+    type = avio_r8(pb);
+    if (type == AMF_DATA_TYPE_MIXEDARRAY)
+        avio_seek(pb, 4, SEEK_CUR);
+    else if (type != AMF_DATA_TYPE_OBJECT)
+        goto out;
+
+    amf_get_string(pb, buf, sizeof(buf));
+    if (strcmp(buf, "type") || avio_r8(pb) != AMF_DATA_TYPE_STRING)
+        goto out;
+
+    amf_get_string(pb, buf, sizeof(buf));
+    //FIXME parse it as codec_id
+    amf_get_string(pb, buf, sizeof(buf));
+    if (strcmp(buf, "text") || avio_r8(pb) != AMF_DATA_TYPE_STRING)
+        goto out;
+
+    length = avio_rb16(pb);
+    ret = av_get_packet(s->pb, pkt, length);
+    if (ret < 0) {
+        ret = AVERROR(EIO);
+        goto out;
+    }
+
+    for (i = 0; i < s->nb_streams; i++) {
+        st = s->streams[i];
+        if (st->id == 2)
+            break;
+    }
+
+    if (i == s->nb_streams) {
+        st = create_stream(s, 2, AVMEDIA_TYPE_DATA);
+        if (!st)
+            goto out;
+        st->codec->codec_id = CODEC_ID_TEXT;
+    }
+
+    pkt->dts  = dts;
+    pkt->pts  = dts;
+    pkt->size = ret;
+
+    pkt->stream_index = st->index;
+    pkt->flags |= AV_PKT_FLAG_KEY;
+
+    avio_seek(s->pb, next + 4, SEEK_SET);
+out:
+    return ret;
+}
+
 static int flv_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     FLVContext *flv = s->priv_data;
@@ -507,7 +580,9 @@ static int flv_read_packet(AVFormatContext *s, AVPacket *pkt)
             goto skip;
     } else {
         if (type == FLV_TAG_TYPE_META && size > 13+1+4)
-            flv_read_metabody(s, next);
+            if (flv_read_metabody(s, next) > 0) {
+                return flv_data_packet(s, pkt, dts, next);
+            }
         else /* skip packet */
             av_log(s, AV_LOG_DEBUG, "skipping flv packet: type %d, size %d, flags %d\n", type, size, flags);
     skip:
@@ -527,7 +602,8 @@ static int flv_read_packet(AVFormatContext *s, AVPacket *pkt)
     }
     if(i == s->nb_streams){
         av_log(s, AV_LOG_ERROR, "invalid stream\n");
-        st= create_stream(s, is_audio);
+        st = create_stream(s, is_audio,
+             is_audio ? AVMEDIA_TYPE_AUDIO : AVMEDIA_TYPE_VIDEO);
         s->ctx_flags &= ~AVFMTCTX_NOHEADER;
     }
     av_dlog(s, "%d %X %d \n", is_audio, flags, st->discard);

libavformat/flvenc.c

@@ -178,7 +178,7 @@ static int flv_write_header(AVFormatContext *s)
 {
     AVIOContext *pb = s->pb;
     FLVContext *flv = s->priv_data;
-    AVCodecContext *audio_enc = NULL, *video_enc = NULL;
+    AVCodecContext *audio_enc = NULL, *video_enc = NULL, *data_enc = NULL;
     int i, metadata_count = 0;
     double framerate = 0.0;
     int64_t metadata_size_pos, data_size, metadata_count_pos;
@@ -187,7 +187,8 @@ static int flv_write_header(AVFormatContext *s)
     for(i=0; i<s->nb_streams; i++){
         AVCodecContext *enc = s->streams[i]->codec;
         FLVStreamContext *sc;
-        if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
+        switch (enc->codec_type) {
+        case AVMEDIA_TYPE_VIDEO:
             if (s->streams[i]->r_frame_rate.den && s->streams[i]->r_frame_rate.num) {
                 framerate = av_q2d(s->streams[i]->r_frame_rate);
             } else {
@@ -198,10 +199,22 @@ static int flv_write_header(AVFormatContext *s)
                 av_log(s, AV_LOG_ERROR, "video codec not compatible with flv\n");
                 return -1;
             }
-        } else {
+            break;
+        case AVMEDIA_TYPE_AUDIO:
             audio_enc = enc;
             if (get_audio_flags(s, enc) < 0)
-                return -1;
+                return AVERROR_INVALIDDATA;
+            break;
+        case AVMEDIA_TYPE_DATA:
+            if (enc->codec_id != CODEC_ID_TEXT) {
+                av_log(s, AV_LOG_ERROR, "codec not compatible with flv\n");
+                return AVERROR_INVALIDDATA;
+            }
+            data_enc = enc;
+            break;
+        default:
+            av_log(s, AV_LOG_ERROR, "codec not compatible with flv\n");
+            return -1;
         }
         avpriv_set_pts_info(s->streams[i], 32, 1, 1000); /* 32 bit pts in ms */
 
@@ -247,7 +260,11 @@ static int flv_write_header(AVFormatContext *s)
     /* mixed array (hash) with size and string/type/data tuples */
     avio_w8(pb, AMF_DATA_TYPE_MIXEDARRAY);
     metadata_count_pos = avio_tell(pb);
-    metadata_count = 5*!!video_enc + 5*!!audio_enc + 2; // +2 for duration and file size
+    metadata_count = 5 * !!video_enc +
+                     5 * !!audio_enc +
+                     1 * !!data_enc +
+                     2; // +2 for duration and file size
+
     avio_wb32(pb, metadata_count);
 
     put_amf_string(pb, "duration");
@@ -288,6 +305,11 @@ static int flv_write_header(AVFormatContext *s)
         put_amf_double(pb, audio_enc->codec_tag);
     }
 
+    if (data_enc) {
+        put_amf_string(pb, "datastream");
+        put_amf_double(pb, 0.0);
+    }
+
     while ((tag = av_dict_get(s->metadata, "", tag, AV_DICT_IGNORE_SUFFIX))) {
         put_amf_string(pb, tag->key);
         avio_w8(pb, AMF_DATA_TYPE_STRING);
@@ -396,7 +418,8 @@ static int flv_write_packet(AVFormatContext *s, AVPacket *pkt)
     else
         flags_size= 1;
 
-    if (enc->codec_type == AVMEDIA_TYPE_VIDEO) {
+    switch (enc->codec_type) {
+    case AVMEDIA_TYPE_VIDEO:
         avio_w8(pb, FLV_TAG_TYPE_VIDEO);
 
         flags = enc->codec_tag;
@@ -406,15 +429,21 @@ static int flv_write_packet(AVFormatContext *s, AVPacket *pkt)
         }
 
         flags |= pkt->flags & AV_PKT_FLAG_KEY ? FLV_FRAME_KEY : FLV_FRAME_INTER;
-    } else {
-        assert(enc->codec_type == AVMEDIA_TYPE_AUDIO);
+        break;
+    case AVMEDIA_TYPE_AUDIO:
         flags = get_audio_flags(s, enc);
 
         assert(size);
 
         avio_w8(pb, FLV_TAG_TYPE_AUDIO);
-    }
+        break;
 
+    case AVMEDIA_TYPE_DATA:
+        avio_w8(pb, FLV_TAG_TYPE_META);
+        break;
+    default:
+        return AVERROR(EINVAL);
+    }
     if (enc->codec_id == CODEC_ID_H264) {
         /* check if extradata looks like MP4 */
         if (enc->extradata_size > 0 && *(uint8_t*)enc->extradata != 1) {
@@ -446,6 +475,29 @@ static int flv_write_packet(AVFormatContext *s, AVPacket *pkt)
     avio_wb24(pb,ts);
     avio_w8(pb,(ts >> 24) & 0x7F); // timestamps are 32bits _signed_
     avio_wb24(pb,flv->reserved);
+
+    if (enc->codec_type == AVMEDIA_TYPE_DATA) {
+        int data_size;
+        int metadata_size_pos = avio_tell(pb);
+        avio_w8(pb, AMF_DATA_TYPE_STRING);
+        put_amf_string(pb, "onTextData");
+        avio_w8(pb, AMF_DATA_TYPE_MIXEDARRAY);
+        avio_wb32(pb, 2);
+        put_amf_string(pb, "type");
+        avio_w8(pb, AMF_DATA_TYPE_STRING);
+        put_amf_string(pb, "Text");
+        put_amf_string(pb, "text");
+        avio_w8(pb, AMF_DATA_TYPE_STRING);
+        put_amf_string(pb, pkt->data);
+        put_amf_string(pb, "");
+        avio_w8(pb, AMF_END_OF_OBJECT);
+        /* write total size of tag */
+        data_size = avio_tell(pb) - metadata_size_pos;
+        avio_seek(pb, metadata_size_pos - 10, SEEK_SET);
+        avio_wb24(pb, data_size);
+        avio_seek(pb, data_size + 10 - 3, SEEK_CUR);
+        avio_wb32(pb, data_size + 11);
+    } else {
     avio_w8(pb,flags);
     if (enc->codec_id == CODEC_ID_VP6)
         avio_w8(pb,0);
@@ -462,7 +514,7 @@ static int flv_write_packet(AVFormatContext *s, AVPacket *pkt)
 
     avio_wb32(pb,size+flags_size+11); // previous tag size
     flv->duration = FFMAX(flv->duration, pkt->pts + flv->delay + pkt->duration);
-
+    }
     avio_flush(pb);
 
     av_free(data);