avcodec/packet_internal: Add proper PacketList struct

Up until now, we had a PacketList structure which is actually
a PacketListEntry; a proper PacketList did not exist
and all the related functions just passed pointers to pointers
to the head and tail elements around. All these pointers were
actually consecutive elements of their containing structs,
i.e. the users already treated them as if they were a struct.

So add a proper PacketList struct and rename the current PacketList
to PacketListEntry; also make the functions use this structure
instead of the pair of pointers.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

1 files changed, 24 insertions, 30 deletions

diff --git a/libavformat/demux.c b/libavformat/demux.c
index 4770e5517f..f895f0ba85 100644
--- a/libavformat/demux.c
+++ b/libavformat/demux.c
@@ -537,7 +537,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
 #endif
 
     for (;;) {
-        PacketList *pktl = si->raw_packet_buffer;
+        PacketListEntry *pktl = si->raw_packet_buffer.head;
         AVStream *st;
         FFStream *sti;
         const AVPacket *pkt1;
@@ -548,8 +548,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
                 if ((err = probe_codec(s, st, NULL)) < 0)
                     return err;
             if (ffstream(st)->request_probe <= 0) {
-                avpriv_packet_list_get(&si->raw_packet_buffer,
-                                       &si->raw_packet_buffer_end, pkt);
+                avpriv_packet_list_get(&si->raw_packet_buffer, pkt);
                 si->raw_packet_buffer_size -= pkt->size;
                 return 0;
             }
@@ -624,13 +623,12 @@ FF_ENABLE_DEPRECATION_WARNINGS
             return 0;
 
         err = avpriv_packet_list_put(&si->raw_packet_buffer,
-                                     &si->raw_packet_buffer_end,
                                      pkt, NULL, 0);
         if (err < 0) {
             av_packet_unref(pkt);
             return err;
         }
-        pkt1 = &si->raw_packet_buffer_end->pkt;
+        pkt1 = &si->raw_packet_buffer.tail->pkt;
         si->raw_packet_buffer_size += pkt1->size;
 
         if ((err = probe_codec(s, st, pkt1)) < 0)
@@ -716,13 +714,14 @@ static int has_decode_delay_been_guessed(AVStream *st)
         return sti->nb_decoded_frames >= 20;
 }
 
-static PacketList *get_next_pkt(AVFormatContext *s, AVStream *st, PacketList *pktl)
+static PacketListEntry *get_next_pkt(AVFormatContext *s, AVStream *st,
+                                     PacketListEntry *pktl)
 {
     FFFormatContext *const si = ffformatcontext(s);
     if (pktl->next)
         return pktl->next;
-    if (pktl == si->packet_buffer_end)
-        return si->parse_queue;
+    if (pktl == si->packet_buffer.tail)
+        return si->parse_queue.head;
     return NULL;
 }
 
@@ -774,7 +773,7 @@ static int64_t select_from_pts_buffer(AVStream *st, int64_t *pts_buffer, int64_t
  * of the packets in a window.
  */
 static void update_dts_from_pts(AVFormatContext *s, int stream_index,
-                                PacketList *pkt_buffer)
+                                PacketListEntry *pkt_buffer)
 {
     AVStream *const st = s->streams[stream_index];
     int delay = ffstream(st)->avctx->has_b_frames;
@@ -804,7 +803,7 @@ static void update_initial_timestamps(AVFormatContext *s, int stream_index,
     FFFormatContext *const si = ffformatcontext(s);
     AVStream *const st  = s->streams[stream_index];
     FFStream *const sti = ffstream(st);
-    PacketList *pktl = si->packet_buffer ? si->packet_buffer : si->parse_queue;
+    PacketListEntry *pktl = si->packet_buffer.head ? si->packet_buffer.head : si->parse_queue.head;
 
     uint64_t shift;
 
@@ -823,7 +822,7 @@ static void update_initial_timestamps(AVFormatContext *s, int stream_index,
     if (is_relative(pts))
         pts += shift;
 
-    for (PacketList *pktl_it = pktl; pktl_it; pktl_it = get_next_pkt(s, st, pktl_it)) {
+    for (PacketListEntry *pktl_it = pktl; pktl_it; pktl_it = get_next_pkt(s, st, pktl_it)) {
         if (pktl_it->pkt.stream_index != stream_index)
             continue;
         if (is_relative(pktl_it->pkt.pts))
@@ -856,7 +855,7 @@ static void update_initial_durations(AVFormatContext *s, AVStream *st,
 {
     FFFormatContext *const si = ffformatcontext(s);
     FFStream *const sti = ffstream(st);
-    PacketList *pktl = si->packet_buffer ? si->packet_buffer : si->parse_queue;
+    PacketListEntry *pktl = si->packet_buffer.head ? si->packet_buffer.head : si->parse_queue.head;
     int64_t cur_dts = RELATIVE_TS_BASE;
 
     if (sti->first_dts != AV_NOPTS_VALUE) {
@@ -882,7 +881,7 @@ static void update_initial_durations(AVFormatContext *s, AVStream *st,
             av_log(s, AV_LOG_DEBUG, "first_dts %s but no packet with dts in the queue\n", av_ts2str(sti->first_dts));
             return;
         }
-        pktl = si->packet_buffer ? si->packet_buffer : si->parse_queue;
+        pktl = si->packet_buffer.head ? si->packet_buffer.head : si->parse_queue.head;
         sti->first_dts = cur_dts;
     } else if (sti->cur_dts != RELATIVE_TS_BASE)
         return;
@@ -998,7 +997,7 @@ static void compute_pkt_fields(AVFormatContext *s, AVStream *st,
         }
     }
 
-    if (pkt->duration > 0 && (si->packet_buffer || si->parse_queue))
+    if (pkt->duration > 0 && (si->packet_buffer.head || si->parse_queue.head))
         update_initial_durations(s, st, pkt->stream_index, pkt->duration);
 
     /* Correct timestamps with byte offset if demuxers only have timestamps
@@ -1195,7 +1194,6 @@ static int parse_packet(AVFormatContext *s, AVPacket *pkt,
         compute_pkt_fields(s, st, sti->parser, out_pkt, next_dts, next_pts);
 
         ret = avpriv_packet_list_put(&si->parse_queue,
-                                     &si->parse_queue_end,
                                      out_pkt, NULL, 0);
         if (ret < 0)
             goto fail;
@@ -1225,7 +1223,7 @@ static int read_frame_internal(AVFormatContext *s, AVPacket *pkt)
     int ret, got_packet = 0;
     AVDictionary *metadata = NULL;
 
-    while (!got_packet && !si->parse_queue) {
+    while (!got_packet && !si->parse_queue.head) {
         AVStream *st;
         FFStream *sti;
 
@@ -1338,8 +1336,8 @@ static int read_frame_internal(AVFormatContext *s, AVPacket *pkt)
         }
     }
 
-    if (!got_packet && si->parse_queue)
-        ret = avpriv_packet_list_get(&si->parse_queue, &si->parse_queue_end, pkt);
+    if (!got_packet && si->parse_queue.head)
+        ret = avpriv_packet_list_get(&si->parse_queue, pkt);
 
     if (ret >= 0) {
         AVStream *const st  = s->streams[pkt->stream_index];
@@ -1420,9 +1418,8 @@ int av_read_frame(AVFormatContext *s, AVPacket *pkt)
     AVStream *st;
 
     if (!genpts) {
-        ret = si->packet_buffer
-              ? avpriv_packet_list_get(&si->packet_buffer,
-                                       &si->packet_buffer_end, pkt)
+        ret = si->packet_buffer.head
+              ? avpriv_packet_list_get(&si->packet_buffer, pkt)
               : read_frame_internal(s, pkt);
         if (ret < 0)
             return ret;
@@ -1430,7 +1427,7 @@ int av_read_frame(AVFormatContext *s, AVPacket *pkt)
     }
 
     for (;;) {
-        PacketList *pktl = si->packet_buffer;
+        PacketListEntry *pktl = si->packet_buffer.head;
 
         if (pktl) {
             AVPacket *next_pkt = &pktl->pkt;
@@ -1463,15 +1460,14 @@ int av_read_frame(AVFormatContext *s, AVPacket *pkt)
                     // 3. the packets for this stream at the end of the files had valid dts.
                     next_pkt->pts = last_dts + next_pkt->duration;
                 }
-                pktl = si->packet_buffer;
+                pktl = si->packet_buffer.head;
             }
 
             /* read packet from packet buffer, if there is data */
             st = s->streams[next_pkt->stream_index];
             if (!(next_pkt->pts == AV_NOPTS_VALUE && st->discard < AVDISCARD_ALL &&
                   next_pkt->dts != AV_NOPTS_VALUE && !eof)) {
-                ret = avpriv_packet_list_get(&si->packet_buffer,
-                                             &si->packet_buffer_end, pkt);
+                ret = avpriv_packet_list_get(&si->packet_buffer, pkt);
                 goto return_packet;
             }
         }
@@ -1486,7 +1482,6 @@ int av_read_frame(AVFormatContext *s, AVPacket *pkt)
         }
 
         ret = avpriv_packet_list_put(&si->packet_buffer,
-                                     &si->packet_buffer_end,
                                      pkt, NULL, 0);
         if (ret < 0) {
             av_packet_unref(pkt);
@@ -2598,12 +2593,11 @@ int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
 
         if (!(ic->flags & AVFMT_FLAG_NOBUFFER)) {
             ret = avpriv_packet_list_put(&si->packet_buffer,
-                                         &si->packet_buffer_end,
                                          pkt1, NULL, 0);
             if (ret < 0)
                 goto unref_then_goto_end;
 
-            pkt = &si->packet_buffer_end->pkt;
+            pkt = &si->packet_buffer.tail->pkt;
         } else {
             pkt = pkt1;
         }
@@ -2751,8 +2745,8 @@ int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
 
             // EOF already reached while reading the stream above.
             // So continue with reoordering DTS with whatever delay we have.
-            if (si->packet_buffer && !has_decode_delay_been_guessed(st)) {
-                update_dts_from_pts(ic, stream_index, si->packet_buffer);
+            if (si->packet_buffer.head && !has_decode_delay_been_guessed(st)) {
+                update_dts_from_pts(ic, stream_index, si->packet_buffer.head);
             }
         }
     }