afh: Dynamic chunks.

[paraslash.git] / aac_afh.c

diff --git a/aac_afh.c b/aac_afh.c
index 1c7fd706f0a7c9fe8c9d4d8db43846be18a9304d..bcf7b785e4bd5518d751b22d5b368e296e43c662 100644 (file)
--- a/aac_afh.c
+++ b/aac_afh.c
@@ -14,6 +14,7 @@
 #include <mp4v2/mp4v2.h>
 
 #include "para.h"
+#include <mp4ff.h>
 #include "error.h"
 #include "portable_io.h"
 #include "afh.h"
@@ -21,6 +22,133 @@
 #include "aac.h"
 #include "fd.h"
 
+struct aac_afh_context {
+       const void *map;
+       size_t mapsize;
+       size_t fpos;
+       int32_t track;
+       mp4ff_t *mp4ff;
+       mp4AudioSpecificConfig masc;
+       mp4ff_callback_t cb;
+};
+
+static uint32_t aac_afh_read_cb(void *user_data, void *dest, uint32_t want)
+{
+       struct aac_afh_context *c = user_data;
+       uint32_t have, rv;
+
+       if (want == 0 || c->fpos >= c->mapsize) {
+               PARA_INFO_LOG("failed attempt to read %u bytes @%zu\n", want,
+                       c->fpos);
+               errno = EAGAIN;
+               return -1;
+       }
+       have = c->mapsize - c->fpos;
+       rv = PARA_MIN(have, want);
+       PARA_DEBUG_LOG("reading %u bytes @%zu\n", rv, c->fpos);
+       memcpy(dest, c->map + c->fpos, rv);
+       c->fpos += rv;
+       return rv;
+}
+
+static uint32_t aac_afh_seek_cb(void *user_data, uint64_t pos)
+{
+       struct aac_afh_context *c = user_data;
+       c->fpos = pos;
+       return 0;
+}
+
+static int32_t aac_afh_get_track(mp4ff_t *mp4ff, mp4AudioSpecificConfig *masc)
+{
+       int32_t i, rc, num_tracks = mp4ff_total_tracks(mp4ff);
+
+       assert(num_tracks >= 0);
+       for (i = 0; i < num_tracks; i++) {
+               unsigned char *buf = NULL;
+               unsigned buf_size = 0;
+
+               mp4ff_get_decoder_config(mp4ff, i, &buf, &buf_size);
+               if (buf) {
+                       rc = NeAACDecAudioSpecificConfig(buf, buf_size, masc);
+                       free(buf);
+                       if (rc < 0)
+                               continue;
+                       return i;
+               }
+       }
+       return -1; /* no audio track */
+}
+
+static int aac_afh_open(const void *map, size_t mapsize, void **afh_context)
+{
+       int ret;
+       struct aac_afh_context *c = para_malloc(sizeof(*c));
+
+       c->map = map;
+       c->mapsize = mapsize;
+       c->fpos = 0;
+       c->cb.read = aac_afh_read_cb;
+       c->cb.seek = aac_afh_seek_cb;
+       c->cb.user_data = c;
+
+       ret = -E_MP4FF_OPEN;
+       c->mp4ff = mp4ff_open_read(&c->cb);
+       if (!c->mp4ff)
+               goto free_ctx;
+       c->track = aac_afh_get_track(c->mp4ff, &c->masc);
+       ret = -E_MP4FF_TRACK;
+       if (c->track < 0)
+               goto close_mp4ff;
+       *afh_context = c;
+       return 0;
+close_mp4ff:
+       mp4ff_close(c->mp4ff);
+free_ctx:
+       free(c);
+       *afh_context = NULL;
+       return ret;
+}
+
+static void aac_afh_close(void *afh_context)
+{
+       struct aac_afh_context *c = afh_context;
+       mp4ff_close(c->mp4ff);
+       free(c);
+}
+
+/**
+ * Libmp4ff function to reposition the file to the given sample.
+ *
+ * \param f The opaque handle returned by mp4ff_open_read().
+ * \param track The number of the (audio) track.
+ * \param sample Destination.
+ *
+ * We need this function to obtain the offset of the sample within the audio
+ * file. Unfortunately, it is not exposed in the mp4ff header.
+ *
+ * \return This function always returns 0.
+ */
+int32_t mp4ff_set_sample_position(mp4ff_t *f, const int32_t track, const int32_t sample);
+
+static int aac_afh_get_chunk(long unsigned chunk_num, void *afh_context,
+               const char **buf, size_t *len)
+{
+       struct aac_afh_context *c = afh_context;
+       int32_t ss;
+       size_t offset;
+
+       assert(chunk_num <= INT_MAX);
+       /* this function always returns zero */
+       mp4ff_set_sample_position(c->mp4ff, c->track, chunk_num);
+       offset = c->fpos;
+       ss = mp4ff_read_sample_getsize(c->mp4ff, c->track, chunk_num);
+       if (ss <= 0)
+               return -E_MP4FF_BAD_SAMPLE;
+       assert(ss + offset <= c->mapsize);
+       *buf = c->map + offset;
+       *len = ss;
+       return 1;
+}
 static int aac_find_stsz(char *buf, size_t buflen, off_t *skip)
 {
        int i;
@@ -183,8 +311,6 @@ static int aac_set_chunk_tv(struct afh_info *afhi,
        struct timeval total;
        long unsigned ms;
 
-       if (!mp4ASC->samplingFrequency)
-               return -E_MP4ASC;
        ms = 1000.0 * afhi->chunks_total * tmp / mp4ASC->samplingFrequency;
        ms2tv(ms, &total);
        tv_divide(afhi->chunks_total, &total, &afhi->chunk_tv);
@@ -242,6 +368,7 @@ static int aac_get_file_info(char *map, size_t numbytes, __a_unused int fd,
        afhi->chunk_table[0] = ret;
        for (i = 1; i<= afhi->chunks_total; i++)
                afhi->chunk_table[i] += ret;
+       set_max_chunk_size(afhi);
        afhi->channels = channels;
        afhi->frequency = rate;
        ret = (afhi->chunk_table[afhi->chunks_total] - afhi->chunk_table[0]) * 8; /* bits */
@@ -327,4 +454,7 @@ void aac_afh_init(struct audio_format_handler *afh)
        afh->get_file_info = aac_get_file_info,
        afh->suffixes = aac_suffixes;
        afh->rewrite_tags = aac_rewrite_tags;
+       afh->open = aac_afh_open;
+       afh->get_chunk = aac_afh_get_chunk;
+       afh->close = aac_afh_close;
 }