a52: fix a52_pointer return value

BugLink: https://github.com/alsa-project/alsa-plugins/issues/28
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

diff --git a/a52/pcm_a52.c b/a52/pcm_a52.c
index d28c8c375044360572fcf86d4577068d3707707c..5409b0a0677d3854fe2da6ccc0659b2a5e895dea 100644 (file)
--- a/a52/pcm_a52.c
+++ b/a52/pcm_a52.c
@@ -96,11 +96,12 @@ struct a52_ctx {
        unsigned char *outbuf1;
        unsigned char *outbuf2;
        int outbuf_size;
-       snd_pcm_uframes_t transfer;
        int remain;
        int filled;
        unsigned int slave_period_size;
        unsigned int slave_buffer_size;
+       snd_pcm_uframes_t pointer;
+       snd_pcm_uframes_t boundary;
        snd_pcm_hw_params_t *hw_params;
 #ifdef USE_AVCODEC_PACKET_ALLOC
        AVPacket *pkt;
@@ -202,9 +203,6 @@ static int write_out_pending(snd_pcm_ioplug_t *io, struct a52_ctx *rec)
        snd_pcm_sframes_t ret;
        unsigned int ofs;
 
-       if (! rec->remain)
-               return 0;
-
        while (rec->remain) {
                ofs = (rec->avctx->frame_size - rec->remain) * 4;
                ret = snd_pcm_writei(rec->slave, rec->outbuf + ofs, rec->remain);
@@ -314,9 +312,12 @@ static int fill_data(snd_pcm_ioplug_t *io,
 
        /* If there are still frames left in outbuf, we can't
         * accept a full a52 frame, because this would overwrite
-        * the frames in outbuf. */
-       if (rec->remain && len)
+        * the frames in outbuf. This should not happen! The a52_pointer()
+        * callback should limit the transferred frames correctly. */
+       if (rec->remain && len) {
+               SNDERR("fill data issue (remain is %i)", rec->remain);
                len--;
+       }
 
        if (size > len)
                size = len;
@@ -410,7 +411,8 @@ static snd_pcm_sframes_t a52_transfer(snd_pcm_ioplug_t *io,
                offset += (unsigned int)err;
                size -= (unsigned int)err;
                result += err;
-               rec->transfer += err;
+               rec->pointer += err;
+               rec->pointer %= rec->boundary;
        } while (size);
        return result > 0 ? result : err;
 }
@@ -423,7 +425,7 @@ static snd_pcm_sframes_t a52_transfer(snd_pcm_ioplug_t *io,
 static snd_pcm_sframes_t a52_pointer(snd_pcm_ioplug_t *io)
 {
        struct a52_ctx *rec = io->private_data;
-       snd_pcm_sframes_t avail;
+       snd_pcm_sframes_t avail, delay;
        snd_pcm_state_t state;
 
        state = snd_pcm_state(rec->slave);
@@ -432,31 +434,26 @@ static snd_pcm_sframes_t a52_pointer(snd_pcm_ioplug_t *io)
        case SND_PCM_STATE_DRAINING:
                break;
        case SND_PCM_STATE_XRUN:
-       case SND_PCM_STATE_SUSPENDED:
                return -EPIPE;
+       case SND_PCM_STATE_SUSPENDED:
+               return -ESTRPIPE;
        default:
                return 0;
        }
 
-       avail = 0;
-
        /* Write what we have from outbuf. */
        write_out_pending(io, rec);
 
-       /* If there is anything remaining in outbuf, we can't
-        * accept any full packets. */
-       if (rec->remain == 0)
-       {
-               /* Round the slave frames to multiples of the packet size. */
-               avail += (snd_pcm_avail_update(rec->slave) / rec->avctx->frame_size) * rec->avctx->frame_size;
-       }
-
+       avail = snd_pcm_avail(rec->slave);
        if (avail < 0)
-               avail = 0;
-       else if ((snd_pcm_uframes_t)avail >= io->buffer_size)
-               avail = io->buffer_size - 1;
+               return avail;
+
+       /* get buffer delay without additional FIFO information */
+       delay = rec->slave_buffer_size - avail;
+       while (delay < 0)
+               delay += rec->slave_buffer_size;
 
-       return (io->appl_ptr + avail) % io->buffer_size;
+       return (rec->pointer - delay - rec->remain - rec->filled) % io->buffer_size;
 }
 
 /* set up the fixed parameters of slave PCM hw_parmas */
@@ -582,6 +579,7 @@ static int a52_sw_params(snd_pcm_ioplug_t *io, snd_pcm_sw_params_t *params)
 
        snd_pcm_sw_params_get_avail_min(params, &avail_min);
        snd_pcm_sw_params_get_start_threshold(params, &start_threshold);
+       snd_pcm_sw_params_get_boundary(params, &rec->boundary);
 
        len = avail_min;
        len += (int)rec->slave_buffer_size - (int)io->buffer_size;
@@ -763,7 +761,7 @@ static int a52_prepare(snd_pcm_ioplug_t *io)
        if (alloc_input_buffer(io))
                return -ENOMEM;
 
-       rec->transfer = 0;
+       rec->pointer = 0;
        rec->remain = 0;
        rec->filled = 0;