[FFmpeg-devel] [PATCH 1/2] avformat/mpegtsenc: Don't use heap allocated array to store pids

Andriy Gelman andriy.gelman at gmail.com
Thu Apr 30 22:57:27 EEST 2020


From: Andriy Gelman <andriy.gelman at gmail.com>

A temporary heap array currently stores pids from all streams.  It is
used to make sure there are no duplicated pids. However, this array is
not needed because the pids from past streams are stored in the
MpegTSWriteStream structs.

Signed-off-by: Andriy Gelman <andriy.gelman at gmail.com>
---
 libavformat/mpegtsenc.c | 51 +++++++++++------------------------------
 1 file changed, 14 insertions(+), 37 deletions(-)

diff --git a/libavformat/mpegtsenc.c b/libavformat/mpegtsenc.c
index f2be6c6632..8ca1ddf003 100644
--- a/libavformat/mpegtsenc.c
+++ b/libavformat/mpegtsenc.c
@@ -931,7 +931,6 @@ static int mpegts_init(AVFormatContext *s)
 {
     MpegTSWrite *ts = s->priv_data;
     int i, j;
-    int *pids;
     int ret;
 
     if (ts->m2ts_mode == -1) {
@@ -989,12 +988,6 @@ static int mpegts_init(AVFormatContext *s)
     ts->sdt.write_packet = section_write_packet;
     ts->sdt.opaque       = s;
 
-    pids = av_malloc_array(s->nb_streams, sizeof(*pids));
-    if (!pids) {
-        ret = AVERROR(ENOMEM);
-        goto fail;
-    }
-
     /* assign pids to each stream */
     for (i = 0; i < s->nb_streams; i++) {
         AVStream *st = s->streams[i];
@@ -1002,8 +995,7 @@ static int mpegts_init(AVFormatContext *s)
 
         ts_st = av_mallocz(sizeof(MpegTSWriteStream));
         if (!ts_st) {
-            ret = AVERROR(ENOMEM);
-            goto fail;
+            return AVERROR(ENOMEM);
         }
         st->priv_data = ts_st;
 
@@ -1011,8 +1003,7 @@ static int mpegts_init(AVFormatContext *s)
 
         ts_st->payload = av_mallocz(ts->pes_payload_size);
         if (!ts_st->payload) {
-            ret = AVERROR(ENOMEM);
-            goto fail;
+            return AVERROR(ENOMEM);
         }
 
         /* MPEG pid values < 16 are reserved. Applications which set st->id in
@@ -1043,8 +1034,7 @@ static int mpegts_init(AVFormatContext *s)
                     ts->m2ts_textsub_pid > M2TS_TEXTSUB_PID + 1        ||
                     ts_st->pid < 16) {
                     av_log(s, AV_LOG_ERROR, "Cannot automatically assign PID for stream %d\n", st->index);
-                    ret = AVERROR(EINVAL);
-                    goto fail;
+                    return AVERROR(EINVAL);
                 }
             } else {
                 ts_st->pid = ts->start_pid + i;
@@ -1055,30 +1045,26 @@ static int mpegts_init(AVFormatContext *s)
         if (ts_st->pid >= 0x1FFF) {
             av_log(s, AV_LOG_ERROR,
                    "Invalid stream id %d, must be less than 8191\n", st->id);
-            ret = AVERROR(EINVAL);
-            goto fail;
+            return AVERROR(EINVAL);
         }
         for (j = 0; j < ts->nb_services; j++) {
             if (ts->services[j]->pmt.pid > LAST_OTHER_PID) {
                 av_log(s, AV_LOG_ERROR,
                        "Invalid PMT PID %d, must be less than %d\n", ts->services[j]->pmt.pid, LAST_OTHER_PID + 1);
-                ret = AVERROR(EINVAL);
-                goto fail;
+                return AVERROR(EINVAL);
             }
             if (ts_st->pid == ts->services[j]->pmt.pid) {
                 av_log(s, AV_LOG_ERROR, "PID %d cannot be both elementary and PMT PID\n", ts_st->pid);
-                ret = AVERROR(EINVAL);
-                goto fail;
+                return AVERROR(EINVAL);
             }
         }
         for (j = 0; j < i; j++) {
-            if (pids[j] == ts_st->pid) {
+            MpegTSWriteStream *ts_st_prev = s->streams[j]->priv_data;
+            if (ts_st_prev->pid == ts_st->pid) {
                 av_log(s, AV_LOG_ERROR, "Duplicate stream id %d\n", ts_st->pid);
-                ret = AVERROR(EINVAL);
-                goto fail;
+                return AVERROR(EINVAL);
             }
         }
-        pids[i]                = ts_st->pid;
         ts_st->payload_pts     = AV_NOPTS_VALUE;
         ts_st->payload_dts     = AV_NOPTS_VALUE;
         ts_st->first_pts_check = 1;
@@ -1089,35 +1075,30 @@ static int mpegts_init(AVFormatContext *s)
             AVStream *ast;
             ts_st->amux = avformat_alloc_context();
             if (!ts_st->amux) {
-                ret = AVERROR(ENOMEM);
-                goto fail;
+                return AVERROR(ENOMEM);
             }
             ts_st->amux->oformat =
                 av_guess_format((ts->flags & MPEGTS_FLAG_AAC_LATM) ? "latm" : "adts",
                                 NULL, NULL);
             if (!ts_st->amux->oformat) {
-                ret = AVERROR(EINVAL);
-                goto fail;
+                return AVERROR(EINVAL);
             }
             if (!(ast = avformat_new_stream(ts_st->amux, NULL))) {
-                ret = AVERROR(ENOMEM);
-                goto fail;
+                return AVERROR(ENOMEM);
             }
             ret = avcodec_parameters_copy(ast->codecpar, st->codecpar);
             if (ret != 0)
-                goto fail;
+                return ret;
             ast->time_base = st->time_base;
             ret = avformat_write_header(ts_st->amux, NULL);
             if (ret < 0)
-                goto fail;
+                return ret;
         }
         if (st->codecpar->codec_id == AV_CODEC_ID_OPUS) {
             ts_st->opus_pending_trim_start = st->codecpar->initial_padding * 48000 / st->codecpar->sample_rate;
         }
     }
 
-    av_freep(&pids);
-
     if (ts->copyts < 1)
         ts->first_pcr = av_rescale(s->max_delay, PCR_TIME_BASE, AV_TIME_BASE);
 
@@ -1138,10 +1119,6 @@ static int mpegts_init(AVFormatContext *s)
            av_rescale(ts->pat_period, 1000, PCR_TIME_BASE));
 
     return 0;
-
-fail:
-    av_freep(&pids);
-    return ret;
 }
 
 /* send SDT, PAT and PMT tables regularly */
-- 
2.25.1



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