lavf: replace AVStream.codec with AVStream.codecpar

Currently, AVStream contains an embedded AVCodecContext instance, which
is used by demuxers to export stream parameters to the caller and by
muxers to receive stream parameters from the caller. It is also used
internally as the codec context that is passed to parsers.

In addition, it is also widely used by the callers as the decoding (when
demuxer) or encoding (when muxing) context, though this has been
officially discouraged since Libav 11.

There are multiple important problems with this approach:
    - the fields in AVCodecContext are in general one of
        * stream parameters
        * codec options
        * codec state
      However, it's not clear which ones are which. It is consequently
      unclear which fields are a demuxer allowed to set or a muxer allowed to
      read. This leads to erratic behaviour depending on whether decoding or
      encoding is being performed or not (and whether it uses the AVStream
      embedded codec context).
    - various synchronization issues arising from the fact that the same
      context is used by several different APIs (muxers/demuxers,
      parsers, bitstream filters and encoders/decoders) simultaneously, with
      there being no clear rules for who can modify what and the different
      processes being typically delayed with respect to each other.
    - avformat_find_stream_info() making it necessary to support opening
      and closing a single codec context multiple times, thus
      complicating the semantics of freeing various allocated objects in the
      codec context.

Those problems are resolved by replacing the AVStream embedded codec
context with a newly added AVCodecParameters instance, which stores only
the stream parameters exported by the demuxers or read by the muxers.

1 files changed, 57 insertions, 57 deletions

diff --git a/libavformat/rmdec.c b/libavformat/rmdec.c
index 5110b0369c..504f111ac0 100644
--- a/libavformat/rmdec.c
+++ b/libavformat/rmdec.c
@@ -82,15 +82,15 @@ static void get_str8(AVIOContext *pb, char *buf, int buf_size)
     get_strl(pb, buf, buf_size, avio_r8(pb));
 }
 
-static int rm_read_extradata(AVIOContext *pb, AVCodecContext *avctx, unsigned size)
+static int rm_read_extradata(AVIOContext *pb, AVCodecParameters *par, unsigned size)
 {
     if (size >= 1<<24)
         return -1;
-    avctx->extradata = av_mallocz(size + AV_INPUT_BUFFER_PADDING_SIZE);
-    if (!avctx->extradata)
+    par->extradata = av_mallocz(size + AV_INPUT_BUFFER_PADDING_SIZE);
+    if (!par->extradata)
         return AVERROR(ENOMEM);
-    avctx->extradata_size = avio_read(pb, avctx->extradata, size);
-    if (avctx->extradata_size != size)
+    par->extradata_size = avio_read(pb, par->extradata, size);
+    if (par->extradata_size != size)
         return AVERROR(EIO);
     return 0;
 }
@@ -142,11 +142,11 @@ static int rm_read_audio_stream_info(AVFormatContext *s, AVIOContext *pb,
         // Skip extra header crap (this should never happen)
         if ((startpos + header_size) > avio_tell(pb))
             avio_skip(pb, header_size + startpos - avio_tell(pb));
-        st->codec->sample_rate = 8000;
-        st->codec->channels = 1;
-        st->codec->channel_layout = AV_CH_LAYOUT_MONO;
-        st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
-        st->codec->codec_id = AV_CODEC_ID_RA_144;
+        st->codecpar->sample_rate = 8000;
+        st->codecpar->channels = 1;
+        st->codecpar->channel_layout = AV_CH_LAYOUT_MONO;
+        st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
+        st->codecpar->codec_id = AV_CODEC_ID_RA_144;
         ast->deint_id = DEINT_ID_INT0;
     } else {
         int flavor, sub_packet_h, coded_framesize, sub_packet_size;
@@ -163,15 +163,15 @@ static int rm_read_audio_stream_info(AVFormatContext *s, AVIOContext *pb,
         avio_rb32(pb); /* ??? */
         avio_rb32(pb); /* ??? */
         ast->sub_packet_h = sub_packet_h = avio_rb16(pb); /* 1 */
-        st->codec->block_align= avio_rb16(pb); /* frame size */
+        st->codecpar->block_align= avio_rb16(pb); /* frame size */
         ast->sub_packet_size = sub_packet_size = avio_rb16(pb); /* sub packet size */
         avio_rb16(pb); /* ??? */
         if (version == 5) {
             avio_rb16(pb); avio_rb16(pb); avio_rb16(pb);
         }
-        st->codec->sample_rate = avio_rb16(pb);
+        st->codecpar->sample_rate = avio_rb16(pb);
         avio_rb32(pb);
-        st->codec->channels = avio_rb16(pb);
+        st->codecpar->channels = avio_rb16(pb);
         if (version == 5) {
             ast->deint_id = avio_rl32(pb);
             avio_read(pb, buf, 4);
@@ -181,19 +181,19 @@ static int rm_read_audio_stream_info(AVFormatContext *s, AVIOContext *pb,
             ast->deint_id = AV_RL32(buf);
             get_str8(pb, buf, sizeof(buf)); /* desc */
         }
-        st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
-        st->codec->codec_tag  = AV_RL32(buf);
-        st->codec->codec_id   = ff_codec_get_id(ff_rm_codec_tags,
-                                                st->codec->codec_tag);
+        st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
+        st->codecpar->codec_tag  = AV_RL32(buf);
+        st->codecpar->codec_id   = ff_codec_get_id(ff_rm_codec_tags,
+                                                   st->codecpar->codec_tag);
 
-        switch (st->codec->codec_id) {
+        switch (st->codecpar->codec_id) {
         case AV_CODEC_ID_AC3:
             st->need_parsing = AVSTREAM_PARSE_FULL;
             break;
         case AV_CODEC_ID_RA_288:
-            st->codec->extradata_size= 0;
-            ast->audio_framesize = st->codec->block_align;
-            st->codec->block_align = coded_framesize;
+            st->codecpar->extradata_size= 0;
+            ast->audio_framesize = st->codecpar->block_align;
+            st->codecpar->block_align = coded_framesize;
             break;
         case AV_CODEC_ID_COOK:
             st->need_parsing = AVSTREAM_PARSE_HEADERS;
@@ -208,22 +208,22 @@ static int rm_read_audio_stream_info(AVFormatContext *s, AVIOContext *pb,
                 return -1;
             }
 
-            ast->audio_framesize = st->codec->block_align;
-            if (st->codec->codec_id == AV_CODEC_ID_SIPR) {
+            ast->audio_framesize = st->codecpar->block_align;
+            if (st->codecpar->codec_id == AV_CODEC_ID_SIPR) {
                 if (flavor > 3) {
                     av_log(s, AV_LOG_ERROR, "bad SIPR file flavor %d\n",
                            flavor);
                     return -1;
                 }
-                st->codec->block_align = ff_sipr_subpk_size[flavor];
+                st->codecpar->block_align = ff_sipr_subpk_size[flavor];
             } else {
                 if(sub_packet_size <= 0){
                     av_log(s, AV_LOG_ERROR, "sub_packet_size is invalid\n");
                     return -1;
                 }
-                st->codec->block_align = ast->sub_packet_size;
+                st->codecpar->block_align = ast->sub_packet_size;
             }
-            if ((ret = rm_read_extradata(pb, st->codec, codecdata_length)) < 0)
+            if ((ret = rm_read_extradata(pb, st->codecpar, codecdata_length)) < 0)
                 return ret;
             break;
         case AV_CODEC_ID_AAC:
@@ -237,7 +237,7 @@ static int rm_read_audio_stream_info(AVFormatContext *s, AVIOContext *pb,
             }
             if (codecdata_length >= 1) {
                 avio_r8(pb);
-                if ((ret = rm_read_extradata(pb, st->codec, codecdata_length - 1)) < 0)
+                if ((ret = rm_read_extradata(pb, st->codecpar, codecdata_length - 1)) < 0)
                     return ret;
             }
             break;
@@ -245,9 +245,9 @@ static int rm_read_audio_stream_info(AVFormatContext *s, AVIOContext *pb,
         if (ast->deint_id == DEINT_ID_INT4 ||
             ast->deint_id == DEINT_ID_GENR ||
             ast->deint_id == DEINT_ID_SIPR) {
-            if (st->codec->block_align <= 0 ||
+            if (st->codecpar->block_align <= 0 ||
                 ast->audio_framesize * sub_packet_h > (unsigned)INT_MAX ||
-                ast->audio_framesize * sub_packet_h < st->codec->block_align)
+                ast->audio_framesize * sub_packet_h < st->codecpar->block_align)
                 return AVERROR_INVALIDDATA;
             if (av_new_packet(&ast->pkt, ast->audio_framesize * sub_packet_h) < 0)
                 return AVERROR(ENOMEM);
@@ -302,13 +302,13 @@ int ff_rm_read_mdpr_codecdata(AVFormatContext *s, AVIOContext *pb,
             return -1;
     } else if (v == MKBETAG('L', 'S', 'D', ':')) {
         avio_seek(pb, -4, SEEK_CUR);
-        if ((ret = rm_read_extradata(pb, st->codec, codec_data_size)) < 0)
+        if ((ret = rm_read_extradata(pb, st->codecpar, codec_data_size)) < 0)
             return ret;
 
-        st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
-        st->codec->codec_tag  = AV_RL32(st->codec->extradata);
-        st->codec->codec_id   = ff_codec_get_id(ff_rm_codec_tags,
-                                                st->codec->codec_tag);
+        st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
+        st->codecpar->codec_tag  = AV_RL32(st->codecpar->extradata);
+        st->codecpar->codec_id   = ff_codec_get_id(ff_rm_codec_tags,
+                                                   st->codecpar->codec_tag);
     } else {
         int fps;
         if (avio_rl32(pb) != MKTAG('V', 'I', 'D', 'O')) {
@@ -316,21 +316,21 @@ int ff_rm_read_mdpr_codecdata(AVFormatContext *s, AVIOContext *pb,
             av_log(s, AV_LOG_WARNING, "Unsupported stream type %08x\n", v);
             goto skip;
         }
-        st->codec->codec_tag = avio_rl32(pb);
-        st->codec->codec_id  = ff_codec_get_id(ff_rm_codec_tags,
-                                               st->codec->codec_tag);
-        av_log(s, AV_LOG_TRACE, "%X %X\n", st->codec->codec_tag, MKTAG('R', 'V', '2', '0'));
-        if (st->codec->codec_id == AV_CODEC_ID_NONE)
+        st->codecpar->codec_tag = avio_rl32(pb);
+        st->codecpar->codec_id  = ff_codec_get_id(ff_rm_codec_tags,
+                                                  st->codecpar->codec_tag);
+        av_log(s, AV_LOG_TRACE, "%X %X\n", st->codecpar->codec_tag, MKTAG('R', 'V', '2', '0'));
+        if (st->codecpar->codec_id == AV_CODEC_ID_NONE)
             goto fail1;
-        st->codec->width  = avio_rb16(pb);
-        st->codec->height = avio_rb16(pb);
+        st->codecpar->width  = avio_rb16(pb);
+        st->codecpar->height = avio_rb16(pb);
         avio_skip(pb, 2); // looks like bits per sample
         avio_skip(pb, 4); // always zero?
-        st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
+        st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
         st->need_parsing = AVSTREAM_PARSE_TIMESTAMPS;
         fps = avio_rb32(pb);
 
-        if ((ret = rm_read_extradata(pb, st->codec, codec_data_size - (avio_tell(pb) - codec_pos))) < 0)
+        if ((ret = rm_read_extradata(pb, st->codecpar, codec_data_size - (avio_tell(pb) - codec_pos))) < 0)
             return ret;
 
         if (fps > 0) {
@@ -485,7 +485,7 @@ static int rm_read_header(AVFormatContext *s)
                 return AVERROR(ENOMEM);
             st->id = avio_rb16(pb);
             avio_rb32(pb); /* max bit rate */
-            st->codec->bit_rate = avio_rb32(pb); /* bit rate */
+            st->codecpar->bit_rate = avio_rb32(pb); /* bit rate */
             avio_rb32(pb); /* max packet size */
             avio_rb32(pb); /* avg packet size */
             start_time = avio_rb32(pb); /* start time */
@@ -495,7 +495,7 @@ static int rm_read_header(AVFormatContext *s)
             st->duration = duration;
             get_str8(pb, buf, sizeof(buf)); /* desc */
             get_str8(pb, buf, sizeof(buf)); /* mimetype */
-            st->codec->codec_type = AVMEDIA_TYPE_DATA;
+            st->codecpar->codec_type = AVMEDIA_TYPE_DATA;
             st->priv_data = ff_rm_alloc_rmstream();
             if (!st->priv_data)
                 return AVERROR(ENOMEM);
@@ -706,7 +706,7 @@ rm_ac3_swap_bytes (AVStream *st, AVPacket *pkt)
     uint8_t *ptr;
     int j;
 
-    if (st->codec->codec_id == AV_CODEC_ID_AC3) {
+    if (st->codecpar->codec_id == AV_CODEC_ID_AC3) {
         ptr = pkt->data;
         for (j=0;j<pkt->size;j+=2) {
             FFSWAP(int, ptr[0], ptr[1]);
@@ -722,11 +722,11 @@ ff_rm_parse_packet (AVFormatContext *s, AVIOContext *pb,
 {
     RMDemuxContext *rm = s->priv_data;
 
-    if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
+    if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
         rm->current_stream= st->id;
         if(rm_assemble_video_frame(s, pb, rm, ast, pkt, len, seq, &timestamp))
             return -1; //got partial frame
-    } else if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
+    } else if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
         if ((ast->deint_id == DEINT_ID_GENR) ||
             (ast->deint_id == DEINT_ID_INT4) ||
             (ast->deint_id == DEINT_ID_SIPR)) {
@@ -763,7 +763,7 @@ ff_rm_parse_packet (AVFormatContext *s, AVIOContext *pb,
 
              ast->sub_packet_cnt = 0;
              rm->audio_stream_num = st->index;
-             rm->audio_pkt_cnt = h * w / st->codec->block_align;
+             rm->audio_pkt_cnt = h * w / st->codecpar->block_align;
         } else if ((ast->deint_id == DEINT_ID_VBRF) ||
                    (ast->deint_id == DEINT_ID_VBRS)) {
             int x;
@@ -786,8 +786,8 @@ ff_rm_parse_packet (AVFormatContext *s, AVIOContext *pb,
     pkt->stream_index = st->index;
 
 #if 0
-    if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
-        if(st->codec->codec_id == AV_CODEC_ID_RV20){
+    if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
+        if(st->codecpar->codec_id == AV_CODEC_ID_RV20){
             int seq= 128*(pkt->data[2]&0x7F) + (pkt->data[3]>>1);
             av_log(s, AV_LOG_DEBUG, "%d %"PRId64" %d\n", *timestamp, *timestamp*512LL/25, seq);
 
@@ -802,7 +802,7 @@ ff_rm_parse_packet (AVFormatContext *s, AVIOContext *pb,
     if (flags & 2)
         pkt->flags |= AV_PKT_FLAG_KEY;
 
-    return st->codec->codec_type == AVMEDIA_TYPE_AUDIO ? rm->audio_pkt_cnt : 0;
+    return st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO ? rm->audio_pkt_cnt : 0;
 }
 
 int
@@ -817,12 +817,12 @@ ff_rm_retrieve_cache (AVFormatContext *s, AVIOContext *pb,
         ast->deint_id == DEINT_ID_VBRS)
         av_get_packet(pb, pkt, ast->sub_packet_lengths[ast->sub_packet_cnt - rm->audio_pkt_cnt]);
     else {
-        int ret = av_new_packet(pkt, st->codec->block_align);
+        int ret = av_new_packet(pkt, st->codecpar->block_align);
         if (ret < 0)
             return ret;
-        memcpy(pkt->data, ast->pkt.data + st->codec->block_align * //FIXME avoid this
-               (ast->sub_packet_h * ast->audio_framesize / st->codec->block_align - rm->audio_pkt_cnt),
-               st->codec->block_align);
+        memcpy(pkt->data, ast->pkt.data + st->codecpar->block_align * //FIXME avoid this
+               (ast->sub_packet_h * ast->audio_framesize / st->codecpar->block_align - rm->audio_pkt_cnt),
+               st->codecpar->block_align);
     }
     rm->audio_pkt_cnt--;
     if ((pkt->pts = ast->audiotimestamp) != AV_NOPTS_VALUE) {
@@ -933,7 +933,7 @@ static int64_t rm_read_dts(AVFormatContext *s, int stream_index,
             return AV_NOPTS_VALUE;
 
         st = s->streams[stream_index2];
-        if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
+        if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
             h= avio_r8(s->pb); len--;
             if(!(h & 0x40)){
                 seq = avio_r8(s->pb); len--;