diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index a5071aa438..be1b2021bd 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -741,6 +741,11 @@ typedef struct RcOverride{
  * Encoders:
  * The encoder needs to be fed with NULL data at the end of encoding until the
  * encoder no longer returns data.
+ *
+ * NOTE: For encoders implementing the AVCodec.encode2() function, setting this
+ *       flag also means that the encoder must set the pts and duration for
+ *       each output packet. If this flag is not set, the pts and duration will
+ *       be determined by libavcodec from the input frame.
  */
 #define CODEC_CAP_DELAY           0x0020
 /**
@@ -793,6 +798,10 @@ typedef struct RcOverride{
  * Codec supports avctx->thread_count == 0 (auto).
  */
 #define CODEC_CAP_AUTO_THREADS     0x8000
+/**
+ * Audio encoder supports receiving a different number of samples in each call.
+ */
+#define CODEC_CAP_VARIABLE_FRAME_SIZE 0x10000
 
 //The following defines may change, don't expect compatibility if you use them.
 #define MB_TYPE_INTRA4x4   0x0001
@@ -3246,6 +3255,19 @@ typedef struct AVCodec {
      * Initialize codec static data, called from avcodec_register().
      */
     void (*init_static_data)(struct AVCodec *codec);
+
+    /**
+     * Encode data to an AVPacket.
+     *
+     * @param      avctx          codec context
+     * @param      avpkt          output AVPacket (may contain a user-provided buffer)
+     * @param[in]  frame          AVFrame containing the raw data to be encoded
+     * @param[out] got_packet_ptr encoder sets to 0 or 1 to indicate that a
+     *                            non-empty packet was returned in avpkt.
+     * @return 0 on success, negative error code on failure
+     */
+    int (*encode2)(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame,
+                   int *got_packet_ptr);
 } AVCodec;
 
 /**
@@ -4213,9 +4235,12 @@ int avcodec_decode_subtitle2(AVCodecContext *avctx, AVSubtitle *sub,
  */
 void avsubtitle_free(AVSubtitle *sub);
 
+#if FF_API_OLD_ENCODE_AUDIO
 /**
  * Encode an audio frame from samples into buf.
  *
+ * @deprecated Use avcodec_encode_audio2 instead.
+ *
  * @note The output buffer should be at least FF_MIN_BUFFER_SIZE bytes large.
  * However, for codecs with avctx->frame_size equal to 0 (e.g. PCM) the user
  * will know how much space is needed because it depends on the value passed
@@ -4235,8 +4260,51 @@ void avsubtitle_free(AVSubtitle *sub);
  * @return On error a negative value is returned, on success zero or the number
  * of bytes used to encode the data read from the input buffer.
  */
-int avcodec_encode_audio(AVCodecContext *avctx, uint8_t *buf, int buf_size,
-                         const short *samples);
+int attribute_deprecated avcodec_encode_audio(AVCodecContext *avctx,
+                                              uint8_t *buf, int buf_size,
+                                              const short *samples);
+#endif
+
+/**
+ * Encode a frame of audio.
+ *
+ * Takes input samples from frame and writes the next output packet, if
+ * available, to avpkt. The output packet does not necessarily contain data for
+ * the most recent frame, as encoders can delay, split, and combine input frames
+ * internally as needed.
+ *
+ * @param avctx     codec context
+ * @param avpkt     output AVPacket.
+ *                  The user can supply an output buffer by setting
+ *                  avpkt->data and avpkt->size prior to calling the
+ *                  function, but if the size of the user-provided data is not
+ *                  large enough, encoding will fail. All other AVPacket fields
+ *                  will be reset by the encoder using av_init_packet(). If
+ *                  avpkt->data is NULL, the encoder will allocate it.
+ *                  The encoder will set avpkt->size to the size of the
+ *                  output packet.
+ * @param[in] frame AVFrame containing the raw audio data to be encoded.
+ *                  May be NULL when flushing an encoder that has the
+ *                  CODEC_CAP_DELAY capability set.
+ *                  There are 2 codec capabilities that affect the allowed
+ *                  values of frame->nb_samples.
+ *                  If CODEC_CAP_SMALL_LAST_FRAME is set, then only the final
+ *                  frame may be smaller than avctx->frame_size, and all other
+ *                  frames must be equal to avctx->frame_size.
+ *                  If CODEC_CAP_VARIABLE_FRAME_SIZE is set, then each frame
+ *                  can have any number of samples.
+ *                  If neither is set, frame->nb_samples must be equal to
+ *                  avctx->frame_size for all frames.
+ * @param[out] got_packet_ptr This field is set to 1 by libavcodec if the
+ *                            output packet is non-empty, and to 0 if it is
+ *                            empty. If the function returns an error, the
+ *                            packet can be assumed to be invalid, and the
+ *                            value of got_packet_ptr is undefined and should
+ *                            not be used.
+ * @return          0 on success, negative error code on failure
+ */
+int avcodec_encode_audio2(AVCodecContext *avctx, AVPacket *avpkt,
+                          const AVFrame *frame, int *got_packet_ptr);
 
 /**
  * Fill audio frame data and linesize.
diff --git a/libavcodec/internal.h b/libavcodec/internal.h
index 1c2d0daaef..441430e41c 100644
--- a/libavcodec/internal.h
+++ b/libavcodec/internal.h
@@ -61,6 +61,14 @@ typedef struct AVCodecInternal {
      * should be freed from the original context only.
      */
     int is_copy;
+
+#if FF_API_OLD_DECODE_AUDIO
+    /**
+     * Internal sample count used by avcodec_encode_audio() to fabricate pts.
+     * Can be removed along with avcodec_encode_audio().
+     */
+    int sample_count;
+#endif
 } AVCodecInternal;
 
 struct AVCodecDefault {
@@ -101,4 +109,21 @@ int avpriv_unlock_avformat(void);
  */
 #define FF_MAX_EXTRADATA_SIZE ((1 << 28) - FF_INPUT_BUFFER_PADDING_SIZE)
 
+/**
+ * Check AVPacket size and/or allocate data.
+ *
+ * Encoders supporting AVCodec.encode2() can use this as a convenience to
+ * ensure the output packet data is large enough, whether provided by the user
+ * or allocated in this function.
+ *
+ * @param avpkt   the AVPacket
+ *                If avpkt->data is already set, avpkt->size is checked
+ *                to ensure it is large enough.
+ *                If avpkt->data is NULL, a new buffer is allocated.
+ *                All other AVPacket fields will be reset with av_init_packet().
+ * @param size    the minimum required packet size
+ * @return        0 on success, negative error code on failure
+ */
+int ff_alloc_packet(AVPacket *avpkt, int size);
+
 #endif /* AVCODEC_INTERNAL_H */
diff --git a/libavcodec/pcm.c b/libavcodec/pcm.c
index 32231125d2..190f027adc 100644
--- a/libavcodec/pcm.c
+++ b/libavcodec/pcm.c
@@ -474,6 +474,7 @@ AVCodec ff_ ## name_ ## _encoder = {            \
     .init        = pcm_encode_init,             \
     .encode      = pcm_encode_frame,            \
     .close       = pcm_encode_close,            \
+    .capabilities = CODEC_CAP_VARIABLE_FRAME_SIZE, \
     .sample_fmts = (const enum AVSampleFormat[]){sample_fmt_,AV_SAMPLE_FMT_NONE}, \
     .long_name = NULL_IF_CONFIG_SMALL(long_name_), \
 }
diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index c3faa76169..ff3f065064 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -25,6 +25,7 @@
  * utils.
  */
 
+#include "libavutil/avassert.h"
 #include "libavutil/avstring.h"
 #include "libavutil/crc.h"
 #include "libavutil/mathematics.h"
@@ -101,6 +102,16 @@ void avcodec_init(void)
     dsputil_static_init();
 }
 
+static av_always_inline int codec_is_encoder(AVCodec *codec)
+{
+    return codec && (codec->encode || codec->encode2);
+}
+
+static av_always_inline int codec_is_decoder(AVCodec *codec)
+{
+    return codec && codec->decode;
+}
+
 void avcodec_register(AVCodec *codec)
 {
     AVCodec **p;
@@ -690,7 +701,7 @@ int attribute_align_arg avcodec_open2(AVCodecContext *avctx, AVCodec *codec, AVD
 
     /* if the decoder init function was already called previously,
        free the already allocated subtitle_header before overwriting it */
-    if (codec->decode)
+    if (codec_is_decoder(codec))
         av_freep(&avctx->subtitle_header);
 
 #define SANE_NB_CHANNELS 128U
@@ -738,7 +749,7 @@ int attribute_align_arg avcodec_open2(AVCodecContext *avctx, AVCodec *codec, AVD
         ret = AVERROR(EINVAL);
         goto free_and_end;
     }
-    if (avctx->codec->encode) {
+    if (codec_is_encoder(avctx->codec)) {
         int i;
         if (avctx->codec->sample_fmts) {
             for (i = 0; avctx->codec->sample_fmts[i] != AV_SAMPLE_FMT_NONE; i++)
@@ -812,20 +823,221 @@ free_and_end:
     goto end;
 }
 
-int attribute_align_arg avcodec_encode_audio(AVCodecContext *avctx, uint8_t *buf, int buf_size,
-                         const short *samples)
+int ff_alloc_packet(AVPacket *avpkt, int size)
 {
-    if(buf_size < FF_MIN_BUFFER_SIZE && 0){
-        av_log(avctx, AV_LOG_ERROR, "buffer smaller than minimum size\n");
-        return -1;
+    if (size > INT_MAX - FF_INPUT_BUFFER_PADDING_SIZE)
+        return AVERROR(EINVAL);
+
+    if (avpkt->data) {
+        uint8_t *pkt_data;
+        int pkt_size;
+
+        if (avpkt->size < size)
+            return AVERROR(EINVAL);
+
+        pkt_data = avpkt->data;
+        pkt_size = avpkt->size;
+        av_init_packet(avpkt);
+        avpkt->data = pkt_data;
+        avpkt->size = pkt_size;
+        return 0;
+    } else {
+        return av_new_packet(avpkt, size);
     }
-    if((avctx->codec->capabilities & CODEC_CAP_DELAY) || samples){
-        int ret = avctx->codec->encode(avctx, buf, buf_size, samples);
-        avctx->frame_number++;
-        return ret;
-    }else
+}
+
+int attribute_align_arg avcodec_encode_audio2(AVCodecContext *avctx,
+                                              AVPacket *avpkt,
+                                              const AVFrame *frame,
+                                              int *got_packet_ptr)
+{
+    int ret;
+    int user_packet = !!avpkt->data;
+    int nb_samples;
+
+    if (!(avctx->codec->capabilities & CODEC_CAP_DELAY) && !frame) {
+        av_init_packet(avpkt);
+        avpkt->size = 0;
         return 0;
+    }
+
+    /* check for valid frame size */
+    if (frame) {
+        nb_samples = frame->nb_samples;
+        if (avctx->codec->capabilities & CODEC_CAP_SMALL_LAST_FRAME) {
+            if (nb_samples > avctx->frame_size)
+                return AVERROR(EINVAL);
+        } else if (!(avctx->codec->capabilities & CODEC_CAP_VARIABLE_FRAME_SIZE)) {
+            if (nb_samples != avctx->frame_size)
+                return AVERROR(EINVAL);
+        }
+    } else {
+        nb_samples = avctx->frame_size;
+    }
+
+    if (avctx->codec->encode2) {
+        *got_packet_ptr = 0;
+        ret = avctx->codec->encode2(avctx, avpkt, frame, got_packet_ptr);
+        if (!ret && *got_packet_ptr &&
+            !(avctx->codec->capabilities & CODEC_CAP_DELAY)) {
+            avpkt->pts = frame->pts;
+            avpkt->duration = av_rescale_q(frame->nb_samples,
+                                           (AVRational){ 1, avctx->sample_rate },
+                                           avctx->time_base);
+        }
+    } else {
+        /* for compatibility with encoders not supporting encode2(), we need to
+           allocate a packet buffer if the user has not provided one or check
+           the size otherwise */
+        int fs_tmp   = 0;
+        int buf_size = avpkt->size;
+        if (!user_packet) {
+            if (avctx->codec->capabilities & CODEC_CAP_VARIABLE_FRAME_SIZE) {
+                av_assert0(av_get_bits_per_sample(avctx->codec_id) != 0);
+                buf_size = nb_samples * avctx->channels *
+                           av_get_bits_per_sample(avctx->codec_id) / 8;
+            } else {
+                /* this is a guess as to the required size.
+                   if an encoder needs more than this, it should probably
+                   implement encode2() */
+                buf_size = 2 * avctx->frame_size * avctx->channels *
+                           av_get_bytes_per_sample(avctx->sample_fmt);
+                buf_size += FF_MIN_BUFFER_SIZE;
+            }
+        }
+        if ((ret = ff_alloc_packet(avpkt, buf_size)))
+            return ret;
+
+        /* Encoders using AVCodec.encode() that support
+           CODEC_CAP_SMALL_LAST_FRAME require avctx->frame_size to be set to
+           the smaller size when encoding the last frame.
+           This code can be removed once all encoders supporting
+           CODEC_CAP_SMALL_LAST_FRAME use encode2() */
+        if ((avctx->codec->capabilities & CODEC_CAP_SMALL_LAST_FRAME) &&
+            nb_samples < avctx->frame_size) {
+            fs_tmp = avctx->frame_size;
+            avctx->frame_size = nb_samples;
+        }
+
+        /* encode the frame */
+        ret = avctx->codec->encode(avctx, avpkt->data, avpkt->size,
+                                   frame ? frame->data[0] : NULL);
+        if (ret >= 0) {
+            if (!ret) {
+                /* no output. if the packet data was allocated by libavcodec,
+                   free it */
+                if (!user_packet)
+                    av_freep(&avpkt->data);
+            } else {
+                if (avctx->coded_frame)
+                    avpkt->pts = avctx->coded_frame->pts;
+                /* Set duration for final small packet. This can be removed
+                   once all encoders supporting CODEC_CAP_SMALL_LAST_FRAME use
+                   encode2() */
+                if (fs_tmp) {
+                    avpkt->duration = av_rescale_q(avctx->frame_size,
+                                                   (AVRational){ 1, avctx->sample_rate },
+                                                   avctx->time_base);
+                }
+            }
+            avpkt->size = ret;
+            *got_packet_ptr = (ret > 0);
+            ret = 0;
+        }
+
+        if (fs_tmp)
+            avctx->frame_size = fs_tmp;
+    }
+    if (!ret)
+        avctx->frame_number++;
+
+    /* NOTE: if we add any audio encoders which output non-keyframe packets,
+             this needs to be moved to the encoders, but for now we can do it
+             here to simplify things */
+    avpkt->flags |= AV_PKT_FLAG_KEY;
+
+    return ret;
+}
+
+#if FF_API_OLD_DECODE_AUDIO
+int attribute_align_arg avcodec_encode_audio(AVCodecContext *avctx,
+                                             uint8_t *buf, int buf_size,
+                                             const short *samples)
+{
+    AVPacket pkt;
+    AVFrame frame0;
+    AVFrame *frame;
+    int ret, samples_size, got_packet;
+
+    av_init_packet(&pkt);
+    pkt.data = buf;
+    pkt.size = buf_size;
+
+    if (samples) {
+        frame = &frame0;
+        avcodec_get_frame_defaults(frame);
+
+        if (avctx->frame_size) {
+            frame->nb_samples = avctx->frame_size;
+        } else {
+            /* if frame_size is not set, the number of samples must be
+               calculated from the buffer size */
+            int64_t nb_samples;
+            if (!av_get_bits_per_sample(avctx->codec_id)) {
+                av_log(avctx, AV_LOG_ERROR, "avcodec_encode_audio() does not "
+                       "support this codec\n");
+                return AVERROR(EINVAL);
+            }
+            nb_samples = (int64_t)buf_size * 8 /
+                         (av_get_bits_per_sample(avctx->codec_id) *
+                         avctx->channels);
+            if (nb_samples >= INT_MAX)
+                return AVERROR(EINVAL);
+            frame->nb_samples = nb_samples;
+        }
+
+        /* it is assumed that the samples buffer is large enough based on the
+           relevant parameters */
+        samples_size = av_samples_get_buffer_size(NULL, avctx->channels,
+                                                  frame->nb_samples,
+                                                  avctx->sample_fmt, 1);
+        if ((ret = avcodec_fill_audio_frame(frame, avctx->channels,
+                                            avctx->sample_fmt,
+                                            samples, samples_size, 1)))
+            return ret;
+
+        /* fabricate frame pts from sample count.
+           this is needed because the avcodec_encode_audio() API does not have
+           a way for the user to provide pts */
+        frame->pts = av_rescale_q(avctx->internal->sample_count,
+                                  (AVRational){ 1, avctx->sample_rate },
+                                  avctx->time_base);
+        avctx->internal->sample_count += frame->nb_samples;
+    } else {
+        frame = NULL;
+    }
+
+    got_packet = 0;
+    ret = avcodec_encode_audio2(avctx, &pkt, frame, &got_packet);
+    if (!ret && got_packet && avctx->coded_frame) {
+        avctx->coded_frame->pts       = pkt.pts;
+        avctx->coded_frame->key_frame = !!(pkt.flags & AV_PKT_FLAG_KEY);
+    }
+    /* free any side data since we cannot return it */
+    if (pkt.side_data_elems > 0) {
+        int i;
+        for (i = 0; i < pkt.side_data_elems; i++)
+            av_free(pkt.side_data[i].data);
+        av_freep(&pkt.side_data);
+        pkt.side_data_elems = 0;
+    }
+
+    if (frame && frame->extended_data != frame->data)
+        av_free(frame->extended_data);
+
+    return ret ? ret : pkt.size;
 }
+#endif
 
 int attribute_align_arg avcodec_encode_video(AVCodecContext *avctx, uint8_t *buf, int buf_size,
                          const AVFrame *pict)
@@ -1077,7 +1289,7 @@ av_cold int avcodec_close(AVCodecContext *avctx)
         av_opt_free(avctx->priv_data);
     av_opt_free(avctx);
     av_freep(&avctx->priv_data);
-    if(avctx->codec && avctx->codec->encode)
+    if (codec_is_encoder(avctx->codec))
         av_freep(&avctx->extradata);
     avctx->codec = NULL;
     avctx->active_thread_type = 0;
@@ -1095,7 +1307,7 @@ AVCodec *avcodec_find_encoder(enum CodecID id)
     AVCodec *p, *experimental=NULL;
     p = first_avcodec;
     while (p) {
-        if (p->encode != NULL && p->id == id) {
+        if (codec_is_encoder(p) && p->id == id) {
             if (p->capabilities & CODEC_CAP_EXPERIMENTAL && !experimental) {
                 experimental = p;
             } else
@@ -1113,7 +1325,7 @@ AVCodec *avcodec_find_encoder_by_name(const char *name)
         return NULL;
     p = first_avcodec;
     while (p) {
-        if (p->encode != NULL && strcmp(name,p->name) == 0)
+        if (codec_is_encoder(p) && strcmp(name,p->name) == 0)
             return p;
         p = p->next;
     }
@@ -1125,7 +1337,7 @@ AVCodec *avcodec_find_decoder(enum CodecID id)
     AVCodec *p;
     p = first_avcodec;
     while (p) {
-        if (p->decode != NULL && p->id == id)
+        if (codec_is_decoder(p) && p->id == id)
             return p;
         p = p->next;
     }
@@ -1139,7 +1351,7 @@ AVCodec *avcodec_find_decoder_by_name(const char *name)
         return NULL;
     p = first_avcodec;
     while (p) {
-        if (p->decode != NULL && strcmp(name,p->name) == 0)
+        if (codec_is_decoder(p) && strcmp(name,p->name) == 0)
             return p;
         p = p->next;
     }
diff --git a/libavcodec/version.h b/libavcodec/version.h
index 87838c08d4..0b7547f2bb 100644
--- a/libavcodec/version.h
+++ b/libavcodec/version.h
@@ -119,5 +119,8 @@
 #ifndef FF_API_AVFRAME_AGE
 #define FF_API_AVFRAME_AGE (LIBAVCODEC_VERSION_MAJOR < 54)
 #endif
+#ifndef FF_API_OLD_ENCODE_AUDIO
+#define FF_API_OLD_ENCODE_AUDIO (LIBAVCODEC_VERSION_MAJOR < 54)
+#endif
 
 #endif /* AVCODEC_VERSION_H */