diff --git a/audio/filter/af_lavcac3enc.c b/audio/filter/af_lavcac3enc.c
index de7d563b76..dc2aeb5045 100644
--- a/audio/filter/af_lavcac3enc.c
+++ b/audio/filter/af_lavcac3enc.c
@@ -34,7 +34,8 @@
 
 #include "config.h"
 #include "af.h"
-#include "audio/reorder_ch.h"
+#include "audio/audio_buffer.h"
+#include "audio/fmt-conversion.h"
 
 
 #define AC3_MAX_CHANNELS 6
@@ -53,10 +54,9 @@ typedef struct af_ac3enc_s {
     bool planarize;
     int add_iec61937_header;
     int bit_rate;
-    int pending_data_size;
-    char *pending_data;
-    int pending_len;
-    int expect_len;
+    struct mp_audio_buffer *pending;
+    int in_samples;     // samples of input per AC3 frame
+    int out_samples;    // upper bound on encoded output per AC3 frame
     int min_channel_num;
     int in_sampleformat;
 } af_ac3enc_t;
@@ -93,17 +93,18 @@ static int control(struct af_instance *af, int cmd, void *arg)
         if (!mp_audio_config_equals(in, &orig_in))
             return AF_FALSE;
 
-        s->pending_len = 0;
-        int expect_samples = AC3_FRAME_SIZE;
-        s->expect_len = expect_samples * in->nch * in->bps;
-        assert(s->expect_len <= s->pending_data_size);
-        if (s->add_iec61937_header)
-            af->mul = 1;
-        else
-            af->mul = (double)(AC3_MAX_CODED_FRAME_SIZE / (2 * 2)) / expect_samples;
+        s->in_samples = AC3_FRAME_SIZE;
+        if (s->add_iec61937_header) {
+            s->out_samples = AC3_FRAME_SIZE;
+        } else {
+            s->out_samples = AC3_MAX_CODED_FRAME_SIZE / af->data->sstride;
+        }
+        af->mul = s->out_samples / (double)s->in_samples;
+
+        mp_audio_buffer_reinit(s->pending, in);
 
         mp_msg(MSGT_AFILTER, MSGL_DBG2, "af_lavcac3enc reinit: %d, %d, %f, %d.\n",
-               in->nch, in->rate, af->mul, s->expect_len);
+               in->nch, in->rate, af->mul, s->in_samples);
 
         bit_rate = s->bit_rate ? s->bit_rate : default_bit_rate[in->nch];
 
@@ -172,83 +173,56 @@ static void uninit(struct af_instance* af)
             avcodec_close(s->lavc_actx);
             av_free(s->lavc_actx);
         }
-        free(s->pending_data);
-        free(s);
     }
 }
 
 // Filter data through filter
 static struct mp_audio* play(struct af_instance* af, struct mp_audio* audio)
 {
+    struct mp_audio *out = af->data;
     af_ac3enc_t *s = af->setup;
-    struct mp_audio *c = audio;    // Current working data
-    struct mp_audio *l;
-    int left, outsize = 0;
-    char *buf, *src;
-    int max_output_len;
-    int frame_num = (mp_audio_psize(audio) + s->pending_len) / s->expect_len;
-    int samplesize = af_fmt2bits(s->in_sampleformat) / 8;
+    int num_frames = (audio->samples + mp_audio_buffer_samples(s->pending))
+                     / s->in_samples;
 
-    if (s->add_iec61937_header)
-        max_output_len = AC3_FRAME_SIZE * 2 * 2 * frame_num;
-    else
-        max_output_len = AC3_MAX_CODED_FRAME_SIZE * frame_num;
+    int max_out_samples = s->out_samples * num_frames;
+    mp_audio_realloc_min(out, max_out_samples);
+    out->samples = 0;
 
-    mp_audio_realloc_min(af->data, max_output_len / af->data->sstride);
-    af->data->samples = max_output_len / af->data->sstride;
-
-    l = af->data;           // Local data
-    buf = l->planes[0];
-    src = c->planes[0];
-    left = mp_audio_psize(c);
-
-
-    while (left > 0) {
+    while (audio->samples > 0) {
         int ret;
 
-        if (left + s->pending_len < s->expect_len) {
-            memcpy(s->pending_data + s->pending_len, src, left);
-            src += left;
-            s->pending_len += left;
-            left = 0;
-            break;
-        }
-
-        char *src2 = src;
-
-        if (s->pending_len) {
-            int needs = s->expect_len - s->pending_len;
-            if (needs > 0) {
-                memcpy(s->pending_data + s->pending_len, src, needs);
-                src += needs;
-                left -= needs;
+        int consumed_pending = 0;
+        struct mp_audio in_frame;
+        int pending = mp_audio_buffer_samples(s->pending);
+        if (pending == 0 && audio->samples >= s->in_samples) {
+            in_frame = *audio;
+            mp_audio_skip_samples(audio, s->in_samples);
+        } else {
+            if (pending > 0 && pending < s->in_samples) {
+                struct mp_audio tmp = *audio;
+                tmp.samples = MPMIN(tmp.samples, s->in_samples);
+                mp_audio_buffer_append(s->pending, &tmp);
+                mp_audio_skip_samples(audio, tmp.samples);
             }
-            src2= s->pending_data;
-        }
-
-        void *data = (void *) src2;
-        if (s->planarize) {
-            void *data2 = malloc(s->expect_len);
-            reorder_to_planar(data2, data, samplesize,
-                    c->nch, s->expect_len / samplesize / c->nch);
-            data = data2;
+            mp_audio_buffer_peek(s->pending, &in_frame);
+            if (in_frame.samples < s->in_samples)
+                break;
+            consumed_pending = s->in_samples;
         }
+        in_frame.samples = s->in_samples;
 
         AVFrame *frame = avcodec_alloc_frame();
         if (!frame) {
             mp_msg(MSGT_AFILTER, MSGL_FATAL, "[libaf] Could not allocate memory \n");
             return NULL;
         }
-        frame->nb_samples = AC3_FRAME_SIZE;
+        frame->nb_samples = s->in_samples;
         frame->format = s->lavc_actx->sample_fmt;
         frame->channel_layout = s->lavc_actx->channel_layout;
-
-        ret = avcodec_fill_audio_frame(frame, c->nch, s->lavc_actx->sample_fmt,
-                                       (const uint8_t*)data, s->expect_len, 0);
-        if (ret < 0) {
-            mp_msg(MSGT_AFILTER, MSGL_FATAL, "[lavac3enc] Frame setup failed.\n");
-            return NULL;
-        }
+        assert(in_frame.num_planes <= AV_NUM_DATA_POINTERS);
+        for (int n = 0; n < in_frame.num_planes; n++)
+            frame->data[n] = in_frame.planes[n];
+        frame->linesize[0] = s->in_samples * audio->sstride;
 
         int ok;
         ret = avcodec_encode_audio2(s->lavc_actx, &s->pkt, frame, &ok);
@@ -257,58 +231,52 @@ static struct mp_audio* play(struct af_instance* af, struct mp_audio* audio)
             return NULL;
         }
 
-        if (s->planarize)
-            free(data);
-
         avcodec_free_frame(&frame);
 
-        if (s->pending_len) {
-            s->pending_len = 0;
-        } else {
-            src += s->expect_len;
-            left -= s->expect_len;
-        }
+        mp_audio_buffer_skip(s->pending, consumed_pending);
 
         mp_msg(MSGT_AFILTER, MSGL_DBG2, "avcodec_encode_audio got %d, pending %d.\n",
-               s->pkt.size, s->pending_len);
+               s->pkt.size, mp_audio_buffer_samples(s->pending));
 
-        int len = s->pkt.size;
+        int frame_size = s->pkt.size;
         int header_len = 0;
-        if (s->add_iec61937_header) {
-            assert(s->pkt.size > 5);
+        char hdr[8];
+
+        if (s->add_iec61937_header && s->pkt.size > 5) {
             int bsmod = s->pkt.data[5] & 0x7;
+            int len = frame_size;
 
-            AV_WB16(buf,     0xF872);   // iec 61937 syncword 1
-            AV_WB16(buf + 2, 0x4E1F);   // iec 61937 syncword 2
-            buf[4] = bsmod;             // bsmod
-            buf[5] = 0x01;              // data-type ac3
-            AV_WB16(buf + 6, len << 3); // number of bits in payload
-
-            memset(buf + 8 + len, 0, AC3_FRAME_SIZE * 2 * 2 - 8 - len);
+            frame_size = AC3_FRAME_SIZE * 2 * 2;
             header_len = 8;
-            len = AC3_FRAME_SIZE * 2 * 2;
+
+            AV_WB16(hdr,     0xF872);   // iec 61937 syncword 1
+            AV_WB16(hdr + 2, 0x4E1F);   // iec 61937 syncword 2
+            hdr[4] = bsmod;             // bsmod
+            hdr[5] = 0x01;              // data-type ac3
+            AV_WB16(hdr + 6, len << 3); // number of bits in payload
         }
 
-        assert(buf + len <= (char *)af->data->planes[0] + mp_audio_psize(af->data));
-        assert(s->pkt.size <= len - header_len);
+        size_t max_size = (max_out_samples - out->samples) * out->sstride;
+        if (frame_size > max_size)
+            abort();
 
+        char *buf = (char *)out->planes[0] + out->samples * out->sstride;
+        memcpy(buf, hdr, header_len);
         memcpy(buf + header_len, s->pkt.data, s->pkt.size);
-
-        outsize += len;
-        buf += len;
+        memset(buf + header_len + s->pkt.size, 0,
+               frame_size - (header_len + s->pkt.size));
+        out->samples += frame_size / out->sstride;
     }
-    c->planes[0] = l->planes[0];
-    mp_audio_set_num_channels(c, 2);
-    mp_audio_set_format(c, af->data->format);
-    c->samples = outsize / c->sstride;
-    mp_msg(MSGT_AFILTER, MSGL_DBG2, "play return size %d, pending %d\n",
-           outsize, s->pending_len);
-    return c;
+
+    mp_audio_buffer_append(s->pending, audio);
+
+    *audio = *out;
+    return audio;
 }
 
 static int af_open(struct af_instance* af){
 
-    af_ac3enc_t *s = calloc(1,sizeof(af_ac3enc_t));
+    af_ac3enc_t *s = talloc_zero(af, af_ac3enc_t);
     af->control=control;
     af->uninit=uninit;
     af->play=play;
@@ -326,45 +294,25 @@ static int af_open(struct af_instance* af){
         return AF_ERROR;
     }
     const enum AVSampleFormat *fmts = s->lavc_acodec->sample_fmts;
-    for (int i = 0; ; i++) {
-        if (fmts[i] == AV_SAMPLE_FMT_NONE) {
-            mp_msg(MSGT_AFILTER, MSGL_ERR, "Audio LAVC, encoder doesn't "
-                   "support expected sample formats!\n");
-            return AF_ERROR;
-        } else if (fmts[i] == AV_SAMPLE_FMT_S16) {
-            s->in_sampleformat = AF_FORMAT_S16_NE;
+    for (int i = 0; fmts[i] != AV_SAMPLE_FMT_NONE; i++) {
+        s->in_sampleformat = af_from_avformat(fmts[i]);
+        if (s->in_sampleformat) {
             s->lavc_actx->sample_fmt = fmts[i];
-            s->planarize = 0;
-            break;
-        } else if (fmts[i] == AV_SAMPLE_FMT_FLT) {
-            s->in_sampleformat = AF_FORMAT_FLOAT_NE;
-            s->lavc_actx->sample_fmt = fmts[i];
-            s->planarize = 0;
-            break;
-        } else if (fmts[i] == AV_SAMPLE_FMT_S16P) {
-            s->in_sampleformat = AF_FORMAT_S16_NE;
-            s->lavc_actx->sample_fmt = fmts[i];
-            s->planarize = 1;
-            break;
-        } else if (fmts[i] == AV_SAMPLE_FMT_FLTP) {
-            s->in_sampleformat = AF_FORMAT_FLOAT_NE;
-            s->lavc_actx->sample_fmt = fmts[i];
-            s->planarize = 1;
             break;
         }
     }
+    if (!s->in_sampleformat) {
+        mp_msg(MSGT_AFILTER, MSGL_ERR, "Audio LAVC, encoder doesn't "
+               "support expected sample formats!\n");
+        return AF_ERROR;
+    }
     mp_msg(MSGT_AFILTER, MSGL_V, "[af_lavcac3enc]: in sample format: %s\n",
            af_fmt_to_str(s->in_sampleformat));
-    s->pending_data_size = AF_NCH * AC3_FRAME_SIZE *
-        af_fmt2bits(s->in_sampleformat) / 8;
-    s->pending_data = malloc(s->pending_data_size);
-
-    if (s->planarize)
-        mp_msg(MSGT_AFILTER, MSGL_WARN,
-                "[af_lavcac3enc]: need to planarize audio data\n");
 
     av_init_packet(&s->pkt);
 
+    s->pending = mp_audio_buffer_create(af);
+
     return AF_OK;
 }